Arabis lemmonii is a species of flowering plant in the family Brassicaceae known by the common name Lemmon's rockcress.

It is native to western North America from Alaska to California to Colorado, where it grows in a number of rocky habitat types.

This is a perennial herb growing many small stems from a branching, hairy caudex.

The slender stems rest against the ground or are somewhat upright, reaching up to 20 centimeters in length.

The inflorescence bears pink to purple flowers which yield narrow siliques up to 4 centimeters long containing round, winged seeds.