Bicycle Infantry are foot-soldiers who maneuver on the battlefield on bicycles. The term dates from the late 19th century, when the "safety bicycle" became popular in Europe, the United States and Australia.

Numerous experiments were carried out to determine the possible role of bicycles within the military establishments. Bicycle units were formed in Great Britain primarily in militia or "territorial" units, but not in regular units. In France, several experimental units were created, mostly employing a series of folding bicycles designed by a French officer. In Italy, the "Bersaglieri" mountain unit employed bicycles until the end of the First World War.

In the United States, the most extensive experimentation on bicycle units was carried out by a 1st Lt Moss, of the 25th United States Infantry (Colored) (an all-Negro infantry regiment with white officers). Using a variety of cycle models, Lt Moss and his troops carried out epic bicycle journey's covering between 500 and 1,000 miles at a time.

The first known use of the bicycle in combat occurred during the so-called "Jameson Raid", which preceded the Second Boer War (1899-1901), where cyclists carried messages. In the Second Boer War, military cyclists were used primarily as scouts and messengers; however, several raids were conducted by cycle-mounted infantry on both sides. A rather unique unit patrolled railroad lines on specially constructed two-man cycles that were fixed to the rails.

During World War 1, cycle-mounted infantry, scouts, messengers and ambulance carriers were extensively used by all combatants. In the aftermath of the war, the German Army conducted a study on the use of the cycle and published its findings in a report entitled "Die Radfahrertruppe".

Although seeing heavy use in World War 1, bicycles were largely superseded by motorized transport in more modern armies, but have recently taken on a new life as a "weapon of the people" in guerrilla conflicts, where the cycle's ability to carry large (c.400lbs/180kg) loads of supplies at the speed of a walking man make it vastly useful for lightly-equipped forces. For extended periods of time, the Viet Cong and North Vietnamese Army used bicycle transport to ferry supplies down the "Ho Chi Minh Trail", avoiding the repeated attacks of United States and Allied bombing raids . Vietnamese "cargo bikes" were rebuilt in jungle workshops with reinforced frames to carry the heavy loads in all terrain.

Bicycles continue in military use today, primarily as an easy alternative for transport on long flightlines. The use of the cycle as an infantry transport tool continued into the 21st Century with the Swiss Army's Bicycle Regiment, which maintained drills for infantry movement and attack until 2001, when the decision was made to phase the unit out.

For further information on the military use of bicycles, see "The Bicycle In Wartime: An Illustrated History", by Jim Fitzpatrick, ISBN: 1574881574, Brassey's Inc.