Astragalus tweedyi, or Tweedy's milkvetch, is a perennial herb in the pea family.

Astragalus tweedyi was described and published in 1890 by William Marriott Canby, who named it in honor of Frank Tweedy, one of the first to collect it, in the hills along the Columbia River in Yakima County, Washington Territory in 1883.

Canby agreed it was closely allied to collinus, but easily distinguished based on leaves and pods, justifying creation of a new species.

[4] Astragalus tweedyi is a much-branched sparsely hairy perennial herb to 50 cm (20 in) high.

[6] It grows on dry, somewhat rocky, hillsides and meadows, from 100–900 m (330–2,950 ft), mostly in a sagebrush-bunchgrass association.