The zhanmadao (Chinese: 斬馬刀; pinyin: zhǎnmǎdāo; Jyutping: zaam2 maa5 dou1; lit. 'horse chopping 'sabre'/'dao'/'single-edged blade'') was a single-bladed anti-cavalry Chinese sword. It originated during the Han dynasty (206 BC – 220 AD) and was especially common in Song China (960–1279).

The zhanmadao is a single-edged sabre with a long broad blade, and a long handle suitable for two-handed use. It was used as an anti-cavalry weapon, dating from Emperor Cheng of Han, made to slice through a horse's legs. This is mentioned in the Wujing Zongyao, a Song military manual from 1072. It featured prominently against the Jin armies in campaigns between 1129 and 1141.

The earliest variant of the zhanmadao is called zhanmajian (Chinese: 斬馬劍; pinyin: zhǎnmǎjiàn), literally "horse beheading jian". The zhanmajian existed during the Han dynasty, so called because it was supposedly able to cut off a horse's head. The difference between the two is that zhanmajian is double-edged whereas the zhanmadao is single-edged, which persists with the meaning of jian and dao. Another suggestion is that the zhanmajian was an execution tool used on special occasions rather than a military weapon.

Surviving examples include a sword that might resemble a nagamaki in construction; it had a wrapped handle 37 cm (15 in) long making it easy to grip with two hands with a blade that was 114 cm (45 in) long and straight, with a slight curve in the last half.

Possible variations of these Chinese swords were the changdao of Tang dynasty and Ming dynasty, wodao of Qing dynasty, as well as miaodao of the Republican Era.