Seidl is a surname. Notable people with the surname include:
- Anton Seidl (1850–1898), Hungarian conductor
- Florian Seidl (born 1979), vehicle designer
- Franziska Seidl (1892–1983), Austrian physicist
- Gabriel von Seidl (1848–1913), German architect
- Johann Gabriel Seidl (1804–1875), Austrian archaeologist, lyricist, narrator and dramatist
- Mario Seidl (born 1992), Austrian nordic combined skier
- Siegfried Seidl (1911–1947), Commander of the concentration camp at Theresienstadt executed for war crimes
- Ulrich Seidl (born 1952), director, screenwriter and producer