Busby is the English name for a military head-dress made of fur. In its first Hungarian form the military busby was a cylindrical fur cap, having a bag of colored cloth hanging from the top. The end of this bag was attached to the right shoulder as a defense against sword-cuts. In Great Britain busbies are of two kinds: (a) the hussar busby, cylindrical in shape, with a bag; this is worn by hussars and the Royal Horse Artillery; (b) the rifle busby, a, folding cap of astrachan (curly lambswool), in shape somewhat resembling a Glengarry but taller. Both have straight plumes in the front of the headdress.

The word busby is also used colloquially to denote the tall bear-and-raccoon-skin caps worn by foot-guards and fusiliers, and the full dress feather bonnet of Highland infantry. Cylindrical busbies were formerly worn by the artillery engineers and rifles, but these are now obsolete in the regular army, though still worn by some territorial and colonial troops of these arms.

Possibly the name's original sense of a busby wig came from association with Dr Richard Busby, headmaster of Westminster School in the late 1600's; but it is also derived from buzz, in the phrase ~ buzz wig.