Tammy may refer to:
- Tam o'shanter, a Scottish hat
- Tammy (film series), a series of four films
- Tammy and the Bachelor, the first film in the series
- "Tammy" (song), a popular song from Tammy and the Bachelor
- Tammy (TV series), a 1965 U.S. television comedy based on the series
- Tammy (comics), a British comic that ran from 1971 to 1984
- Tammy (given name)
- Tammy (doll), a fashion doll created by the Ideal Toy Company in response to Mattel's Barbie doll
- Tammy, a British girls' fashion store chain, purchased by and incorporated into Bhs stores after 2005