Aja is both a surname and a given name; as the latter, it is sometimes rendered as A'ja. Notable people with the name include:
Surname:
- Alexandre Aja (born 1978), French filmmaker
- David Aja, Spanish comic book artist
- Gonzalo Aja (born 1946), Spanish former road bicycle racer
- Pablo Aja (born 1986), Mexican footballer
Given name:
- Aja Brown (born 1982), American politician
- Aja Evans (born 1988), American bobsledder
- Aja Huang (born 1978), Taiwanese computer scientist
- Aja Jerman (born 1999), Slovenian rhythmic gymnast
- Aja Kim, American singer and songwriter
- Aja Naomi King (born 1985), American actress
- Aja Kong (born 1970), Japanese professional wrestler
- Aja Monet (born 1987), American contemporary poet, writer, lyricist, and activist
- Aja Volkman (born 1980), American singer and songwriter
- Aja West, American musician
- A'ja Wilson (born 1996), American basketball player
- Aja (entertainer), contestant on RuPaul's Drag Race