
A bayonet is a knife, dagger, sword, or spike-shaped weapon designed to fit on the end of the muzzle of a rifle, musket or similar firearm, allowing it to be used as a spear. From the 17th century to World War I, it was considered a primary weapon for infantry attacks. Today, it is considered an ancillary weapon or a weapon of last resort.

A knife bayonet is a knife which can be used both as a bayonet, combat knife, or utility knife. The knife bayonet became the almost universal form of bayonet in the 20th century due to its versatility and effectiveness. Spike bayonets proved useless when separated from the rifle and useless in trench warfare; and while versatile, sword bayonets proved to be impractical weapons in trench warfare because of their length. The first knife bayonet to see widespread service was the 10 inch blade Seitengewehr 1871/84, which became the standard German infantry bayonet in 1884. Its derivative, the Seitengewehr 1884/98, would go on in use until 1945 in German service.

A spike bayonet, also known as a pigsticker in informal contexts, is a blade attachment for a firearm taking the form of a pointed spike rather than a knife.
The Glock knife is a military field knife product line designed and produced by Glock Ges.m.b.H., located in Deutsch-Wagram, Austria. It can also be used as a bayonet, by engaging a socket in the pommel into a bayonet adapter that can be fitted to the Steyr AUG rifle.

The Hanyang M1935 bayonet is a bayonet used on the Chinese Chiang Kai-Shek rifle. It is based on the Mauser S84/98 III bayonet used on German Gewehr 98 rifles and derivatives.
Jūkendō (銃剣道) is the Japanese martial art of bayonet fighting, and has been likened to kendo.

The Pattern 1907 bayonet, officially called the Sword bayonet, pattern 1907 , was a British bayonet designed to be used with the Short Magazine Lee Enfield (SMLE) rifle. The Pattern 1907 bayonet was used by the British and Commonwealth forces throughout both the First and Second World Wars.

The Seitengewehr 98, also known as the "Butcher's Blade", is a bayonet used with the Gewehr 98 rifle by Germany. It was designed in response to the French Épée-Baïonnette Modèle 1886.

The Type 30 bayonet was a bayonet designed for the Imperial Japanese Army to be used with the Arisaka Type 30 Rifle and was later used on the Type 38 and Type 99 rifles. Some 8.4 million were produced, and it remained in front-line use from the Russo-Japanese War to the end of World War II. All Japanese infantrymen were issued with the Type 30, whether they were armed with a rifle or pistol, or even if they were unarmed.