Ondřej Trojan (born 31 December 1959 in Prague) is a Czech film and theater actor, director and producer. He comes from an artistic family, father Ladislav Trojan and younger brother Ivan are Czech actors. After graduating from the FAMU in Prague in 1991, he made his debut with the film Let's Sing a Song by screenwriters Jan Hřebejko and Petr Jarchovský. The second feature film was the very successful film Želary based on the short story by Jozova Hanula by Květa Legátová, which was nominated eleven times for the Czech Lion Award as well as the American Academy of Motion Picture Arts and Sciences Oscar. In 2010, Trojan directed and produced his third film, an Identity Card. In 2018, he released his fourth film, Toman, in cinemas.

He focuses on theater directing and acting in the legendary Prague Theater Sklep. Together with Tomáš Hanák and Jiří Fero Burda, they founded their own production and trading company Total HelpArt T.H.A. In 1994, he directed a television recording of the cellar adaptation of Václav Havel and Karel Brynda's play Life Before Himself, which the Sklep Theater presented in an adapted version called Mlýny. He also played several small roles in the films Journey from the City, Elf, Farm Manager, Gympl and The Decadent Visitor. As a producer, he collaborates mainly with director Jan Hřebejk. Together they prepared the films Pelíšky, We Must Help Ourselves, Pupendo, Up and Down, Beauty in Trouble, Teddy Bear and Good to Me.