As nouns the difference between baroness and baronet

is that baroness is the female ruler of a barony. The male equivalent is baron while baronet is a hereditary title, below a peerage and senior to most knighthoods, entitling the bearer to the titular prefix "Sir" (for men) or "Dame" (for women) which is used in conjunction with the holder's Christian name. It is inheritable, usually by the eldest son although a few baronetcies can also pass through the female line.