1721, "lollipop;" 1778, "lover, sweetheart," from sweet (n.) + -ie.
Entries linking to sweetie
sweet n.
c. 1300, "something sweet to the taste," also "beloved one," from sweet (adj.); the specific meaning "candy drop" is 1851 (earlier sweetie, 1721). Meaning "one who is dear to another" is from 14c. Old English swete (n.) meant "sweetness."
-ie
alternative spelling of -y; now mostly of -y (3), but formerly of the others as well.