小酸模（学名：Rumex acetosella），蓼科多年生草本植物。原生于欧亚大陆，被广泛引入到北半球其余区域。

Rumex acetosella is a species of sorrel, bearing the common names sheep's sorrel, red sorrel, sour weed, and field sorrel. The plant and its subspecies are common perennial weeds. It has green arrowhead-shaped leaves and red-tinted deeply ridged stems, and it sprouts from an aggressive and spreading rhizome. The flowers emerge from a tall, upright stem. Female flowers are maroon in color.