Sir Andrew Agnew, 3rd Baronet (died 1702) was a Scottish member of parliament who was the son of Sir Andrew Agnew, 2nd Baronet and Lady Anne Stewart.
He succeeded his father as 3rd Baronet Agnew, of Lochnaw on the latter's death in 1671. On his death in 1702 he was succeeded in the baronetcy by his third son, his elder sons having predeceased him.
He was member of parliament for Wigtownshire in 1685 and 1689–1702.
He married Jane Hay, daughter of Thomas Hay and Jean Hamilton (24 October 1656), and had issue: