
Michelle Alexander is a writer, civil rights advocate, and visiting professor at Union Theological Seminary. She is best known for her 2010 book The New Jim Crow: Mass Incarceration in the Age of Colorblindness, and is an opinion columnist for The New York Times.

Comte Gustave Auguste Bonnin de la Bonninière de Beaumont was a French magistrate, prison reformer, and travel companion to the famed philosopher and politician Alexis de Tocqueville. While he was very successful in his lifetime, he is often overlooked and his name is synonymous with Tocqueville's achievements.

Kiran Bedi is an Indian politician, social activist, retired police officer and tennis player, who was the 24th Lieutenant Governor of Puducherry from 28 May 2016 to 16 February 2021. She is the first Indian female to become an officer in the Indian Police Service and started her service in 1972. She remained in service for 35 years before taking voluntary retirement in 2007 as Director General, Bureau of Police Research and Development.

Zebulon Reed Brockway was a penologist and is sometimes regarded as the "Father of prison reform" and "Father of American Parole" in the United States.

Helen Louise Bullock was a musical educator, temperance reformer, women's prison reformer, suffragist, and philanthropist from the U.S. state of New York. For 35 years, she taught piano, organ and guitar. She gave up her profession of music, in which she had achieved some prominence, to become a practical volunteer in the work for suffrage and temperance. In 1889, she was appointed national organizer of the Woman's Christian Temperance Union (WCTU) and in that work went from Maine to California, traveling 13,000 miles (21,000 km) in one year. During the first five years of her work, she held over 1,200 meetings, organizing 108 new unions and secured over 10,000 new members, active and honorary. She received in one year the largest two prizes ever given by the national WCTU for organizing work.

Susan Burton is an activist based in Los Angeles, United States who works with formerly incarcerated people and founded the nonprofit organization, A New Way of Life. She was named a CNN Hero in 2010 and a Purpose Prize winner in 2012.

Cori Anika Bush is an American politician, registered nurse, pastor, and activist serving as the U.S. Representative for Missouri's 1st congressional district. The district includes all of the city of St. Louis and most of northern St. Louis County.

Dame Geraldine Southall Cadbury, DBE was a British Quaker, author, social and penal reformer. She was the wife of Barrow Cadbury, with whom she had three children, Dorothy Adlington, (1892–1987), Paul Strangman (1895–1984), and Geraldine Mary, (1900–1999).

Hannah B. Chickering was a prison reformer in the late 1800s, who worked to establish separate prisons for female inmates in Massachusetts and founded the Temporary Asylum for discharged female prisoners which later became known as the Dedham Temporary Home for Women and Children, which operated between 1864 and 1969 in Dedham, MA.

Margaret L. Taylor Curry was an American state parole officer, medical social worker, child welfare worker, and music teacher. In 1952 she became the first female parole officer for the Colorado Department of Corrections. During her 18-year tenure, she was the only female officer supervising adult inmates and parolees. She introduced vocational training, high school equivalency courses, and self-improvement classes to further the rehabilitation of women prisoners. She was inducted into the Colorado Women's Hall of Fame in 1996.

Berkeley "Bert" Lionel Scudamore Dallard was a New Zealand accountant, senior public servant and prison administrator.

Marcos Fernandes de Omena, most known as Dexter, is a Brazilian rapper.

Carl Dix is a founding member, and a representative, of the Revolutionary Communist Party, USA (RCP). He is a regular contributor to Revolution newspaper and a longtime associate of Bob Avakian.

Dorothea Lynde Dix was an American advocate on behalf of the indigent mentally ill who, through a vigorous and sustained program of lobbying state legislatures and the United States Congress, created the first generation of American mental asylums. During the Civil War, she served as a Superintendent of Army Nurses.

Stephen Donaldson, born Robert Anthony Martin Jr and also known by the pseudonym Donny the Punk, was an American bisexual rights activist, and political activist. He is best known for his pioneering activism in LGBT rights and prison reform, and for his writing about punk rock and subculture.

Elizabeth Fry, sometimes referred to as Betsy Fry, was an English prison reformer, social reformer and, as a Quaker, a Quaker philanthropist. She has been called the "angel of prisons". Fry was a major driving force behind new legislation to make the treatment of prisoners more humane, especially those of female inmates, with the disadvantages faced by all prisoners compounded by female vulnerability disadvantage in relation to both male prisoners and warders. She was instrumental in the 1823 Gaols Act which mandated i) sex-segregation of prisons and ii) female warders for female inmates to protect them from sexual exploitation. As most Quakers since the foundation of Quakerism from 1650's, Fry kept extensive diaries in which the need to protect female prisoners from rape and sexual exploitation is explicit. She was supported in her efforts by Queen Victoria and by both Emperor Alexander I and Emperor Nicholas I of Russia and was in correspondence with both of the Imperial brothers, their wives and the Empress Mother as documented in her own journal and that of other contemporary Quakers. Journals of Stephen Grellet & William Allen She was depicted on the Bank of England £5 note, in circulation 2002-2016 and along with the female prisoners at Newgate, who benefited from her care and the campaigning work she did including giving evidence in Parliament. She worked tirelessly to ameliorate prison conditions, including the end-to-end care of women and girls deported to Botany Bay.

Sara Margery Fry was a British prison reformer as well as one of the first women to become a magistrate. She was the secretary of the Howard League for Penal Reform and the principal of Somerville College, Oxford.

Mariana Wright Chapman was an American social reformer and women's rights activist. Her most active work was in the direction of prison reform and equal rights for women. Chapman was well-known through her work in the Hicksite Society of Friends, of which she was one of the organizers, and because of her advocacy of woman's suffrage. Chapman was president of the Woman Suffrage Association of Brooklyn, which office she resigned to become president of the New York State Woman Suffrage Association.

Miss Major Griffin-Gracy, often referred to as Miss Major, is a trans woman activist and community leader for transgender rights, with a particular focus on women of color. She served as the original Executive Director for the Transgender Gender Variant Intersex Justice Project, which aims to assist transgender persons, who are disproportionately incarcerated under the prison-industrial complex. Griffin-Gracy has participated in activism for a wide range of causes throughout her lifetime, including the 1969 Stonewall riots in New York City.

Rosamond Davenport Hill was a British educational administrator and prison reformer.

Jessie Donaldson Hodder was a women's prison reformer.

John Howard FRS was a philanthropist and early English prison reformer.

George Cecil Ives was an English poet, writer, penal reformer and early homosexual law reform campaigner.

Ellen Cheney Johnson, American prison reformer, founded the New England Women's Auxiliary Association to the United States Sanitary Commission, worked with homeless and vagrant women after the Civil War through the Dedham Asylum for Discharged Female Prisoners, and served as superintendent of the Massachusetts Reformatory Prison for Women at Framingham.

Tishaura Oneda Jones is an American politician from St. Louis, Missouri. Since 2021, she has served as the mayor of St. Louis, the first African-American woman to hold the position. A member of the Democratic Party, Jones was previously elected to the Missouri House of Representatives to represent the 63rd district in 2008, serving until 2013. She was Treasurer of St. Louis from 2013 to 2021.

Piper Eressea Kerman is an American author who was indicted in 1998, on charges of felonious money-laundering activities, and sentenced to 15 months' detention in a federal correctional facility, of which she eventually served 13 months. Her memoir of her prison experiences, Orange Is the New Black: My Year in a Women's Prison, was adapted into the critically acclaimed Netflix original comedy-drama series Orange Is the New Black. Since leaving prison, Kerman has spoken widely about women in prison and about her own experiences there. She now works as a communication strategist for non-profit organizations.

Lawrence Robert Lawton is an American ex-convict, author, motivational speaker, and YouTuber. Lawton gained notoriety for committing a string of jewelry store robberies along the Atlantic Seaboard prior to his arrest in 1996. He spent eleven years in prison, and once released, began a career as a motivational speaker, life coach, and author.

Francis Aungier Pakenham, 7th Earl of Longford, 1st Baron Pakenham, Baron Pakenham of Cowley, known to his family as Frank Longford and styled Lord Pakenham from 1945 to 1961, was a British politician and social reformer. A member of the Labour Party, he was one of its longest-serving politicians. He held cabinet positions on several occasions between 1947 and 1968. Longford was politically active until his death in 2001. A member of an old, landed Anglo-Irish family, the Pakenhams, he was one of the few aristocratic hereditary peers ever to serve in a senior capacity within a Labour government.

Charles (Jean-Marie) Lucas, born in Saint-Brieuc, on 9 May 1803, died in Paris on 20 December 1889) was a French prison reformer.

Edmund Allen Meredith was an Irish lawyer whose career was in public service in Canada. He was Under Secretary of State for Canada; a prison reformer, writer, president of the Literary and Historical Society of Quebec and the third principal of McGill University from 1846 to 1853. The diary he kept from 1844 until his death is preserved in the National Archives of Canada and formed the basis for the first half of Sandra Gwyn's book The Private Capital: Ambition and Love in the Age of Macdonald and Laurier (1985), which the CBC later made into a television series.

Mary Rhodes Moorhouse-Pekkala was a British-born Finnish patronage and civil rights activist, who was an heiress to a wealthy New Zealand-British family. In the early 1920s, she was active in the Communist Party of Great Britain and the Comintern. Moorhouse emigrated to Finland in 1928 after marrying the Finnish Socialist politician Eino Pekkala. She was one of the major financiers of the 1930s Finnish cultural left, and a prominent civil rights activist.

Vartika Nanda is Indian prison reformer and media educator. She is the founder of Tinka Tinka, a movement targeted towards prison reforms. She has received the Stree Shakti Puraskar award from the President of India, Shri Pranab Mukherjee, the highest civilian honour for women in India on women empowerment. It was conferred to her on International Women's Day 2014 in Rashtrapati Bhavan in recognition of her contribution towards creating awareness about women's issues through media and literature. Her novel work in the field of prison reforms has been recognized by the Limca Book of Records twice.

James Neild was an English jeweller and prison reformer. While he was supported by two particular friends, Weeden Butler and John Coakley Lettsom, his efforts were distinct from those of John Howard, and the Quaker group including Elizabeth Fry.

Thomas Mott Osborne was an American prison administrator, prison reformer, industrialist and New York State political reformer. In an assessment of Osborne's life, a New York Times book reviewer wrote: "His career as a penologist was short, but in the interval of the few years he served he succeeded in revolutionizing American prison reform, if not always in fact, then in awakening responsibility.... He was made of the spectacular stuff of martyrs, to many people perhaps ridiculous, but to those whose lives his theories most closely touched, inspiring and often godlike."

Nettie Podell Ottenberg was a Russian-born American social worker. She was one of the first trained social workers in the United States. An advocate for women's suffrage, voting rights for Washington, D.C., and childcare, in the 1960s she won the first federal funding for daycare and the nickname “The Mother of Daycare”.

Helen Prejean, C.S.J. is a Roman Catholic sister, a member of the Congregation of St. Joseph based in New Orleans, and a leading American advocate for the abolition of the death penalty.

Ayanna Soyini Pressley is an American politician who is serving as the U.S. Representative for Massachusetts's 7th congressional district since 2019. Her district includes the northern three quarters of Boston, most of Cambridge, and parts of Milton, as well as all of Chelsea, Everett, Randolph, and Somerville.
Clara Dorothea Tabor Rackham was an English feminist and politician active in the women's suffrage movement, the Women's Co-operative Guild, the peace movement, adult education, the family planning movement, and the labour movement. She was a pioneering magistrate, Poor Law Guardian, educator, anti-poverty campaigner and penal reformer in the city of Cambridge where she was a long-serving city and county councillor. Clara Rackham was vice-chairman of Cambridge County Council from 1956 to 1958 and chairman of the Cambridge County Council Education Committee from 1945 to 1957. She first came to prominence through her leading role in the National Union of Women's Suffrage Societies and later became a significant national figure in the labour movement, acquiring a formidable national reputation for her expertise on factory conditions, workers' rights, equal pay, and national insurance.

Roger Irving Pryke was a scholar, Catholic priest, psychologist, and social activist who left an indelible impression on the Australian Catholic community and on the broader Australian community. As a priest he was a knowledgeable precursor, and later exponent, of the reforms of the Second Vatican Council. As a preacher, lecturer and personal counsellor he was acknowledged as "(changing) thousands of people's lives" and influencing those thousands into "(becoming) a new kind of Catholic". As a personal guide to many, he applied the principles of psychology to the enrichment of the Christian life to great effect. His compelling social conscience led to his public involvement in issues such as apartheid in South Africa, the Vietnam War, and within the Church community, a leadership role and deep involvement, inter alia, in the reform of the Catholic Liturgy.

Michael Gerard Santos is an American prison consultant, author of several books about prison, a professor of criminal justice, and an advocate for criminal justice reform. Santos spent twenty-six years inside nineteen different United States federal prisons. During his decades inside federal prison, Santos committed to transforming his life, obtained an education, got married, wrote several books, blogged, and worked to prepare himself for a successful law-abiding life. Santos served more than twenty-six years of a forty-five year sentence.

Ernestine Schaffner was a German-born American prison reformer. She was the first to do volunteer missionary work among those detained in the New York City Prison, known as The Tombs, having the financial means to indulge her charitable leanings in a substantial way. Daily, she left her luxurious home in New York City to try and right some of the wrongs inflicted by society and the law. In 1890, Schaffner's philanthropic work had grown to be so extensive that she engaged a salaried lawyer to attend to the legal part of it, and at the same time, she opened an office near The Tombs at 23 Centre Street. Here she advertised: ‘Free Advice to the Poor and the Innocent Accused.’ Schaffner was regularly out US$20,000 in bail bonds, and she had a considerable sum lent to those who had been prisoners. She and Rebecca Salome Foster were known as "The Angels of the Tombs".

Bryan Stevenson is an American lawyer, social justice activist, founder/executive director of the Equal Justice Initiative, and a law professor at New York University School of Law. Based in Montgomery, Alabama, Stevenson has challenged bias against the poor and minorities in the criminal justice system, especially children. He has helped achieve United States Supreme Court decisions that prohibit sentencing children under 18 to death or to life imprisonment without parole. Stevenson has assisted in cases that have saved dozens of prisoners from the death penalty, advocated for the poor, and developed community-based reform litigation aimed at improving the administration of criminal justice.

Miriam Van Waters was an American prison reformer of the early to mid-20th century whose methods owed much to her upbringing as an Episcopalian involved in the Social Gospel movement. During her career as a penologist, which spanned most of the years from 1914 through 1957, she served as superintendent of three prisons: Frazier Detention Home for boys and girls in Portland, Oregon; Los Angeles County Juvenile Hall for girls, and the Massachusetts Correctional Institution – Framingham, then called the Massachusetts Reformatory for Women. While in California, Van Waters established an experimental reformatory school, El Retiro, for girls age 14 to 19. In each case, Van Waters developed programs that favored education, work, recreation, and a sense of community over unalloyed incarceration and punishment.

Walter Venning (1781–1821) was an English merchant and philanthropist, interested in prison reform.

Sir Peter Alderidge Williams was a New Zealand barrister and penal reform advocate. He was appointed a Queen's Counsel in 1987.

Sir Robert Kinsela Workman, commonly known as Kim Workman, is a New Zealand criminal justice advocate.