Ahl is a surname. Notable people with the surname include:
- David H. Ahl (born 1939), American writer
- Ernst Ahl (1898–1945), German zoologist
- Frederick Ahl (born 1941), American academic and classical scholar
- John Alexander Ahl (1813–1882), American railroad executive and politician
- Kennet Ahl, pseudonym of Swedish crime novelist duo Lasse Strömstedt and Christer Dahl