A bolo is a kind of machete, used particularly in the jungles of Indonesia, the Philippines, and in the sugar fields of Cuba. Like other machetes it is primarily intended for clearing vegetation (whether for agriculture or during trailblazing). Bolos are also used as military weapons. Such bolo knives were a particular favorite of the Filipino resistance during the Philippine Revolution against Spain, the Philippine-American War, and the Commonwealth period. For this reason the study of the bolo is common in the Filipino martial arts.

Bolos are particularly characterized by having a native hardwood handle, a full tang, and by a blade that both curves and gets wider (often considerably so) nearer to the tip. This moves the centre of gravity as far forward as possible, giving the knife extra momentum for chopping difficult vegetation. So-called jungle bolos or itak in Tagalog, intended for combat more than agricultural work, tend to be a little longer and less wide at the tip.

In the US military, the slang term "to Bolo" which means a test, exam or evaluation came from the Philippine/American guerrilla forces in World War II; those guerrillas who failed to demonstrate proficiency in marksmanship were issued bolos instead of firearms so as not to waste the scarce ammunition.