The name Alfalfa may refer to any of the following:
- Alfalfa (scientific name Medicago sativa, a.k.a. lucerne), a perennial flowering plant mostly used as a forage crop for livestock
- an unincorporated community in Oregon in the US, named after the plant
- a county in Oklahoma in the US
- a character in the Our Gang and Little Rascals franchises
- ALFALFA, a radioastronomy research project located at the Arecibo Observatory in Puerto Rico