Petr Lněnička (born July 20, 1979 in Litomyšl) is a Czech theater and film actor and member of the Kašpar theater company. He studied drama at DAMU. While still a student, he appeared as a guest performer at the Vinohrady Theater and the National Theater. After graduating, he joined the Kašpar theater company, where he still performs in most productions.

He is also involved in radio and dubbing work. He is the "voice" of Czech Radio's Radiožurnál station. He currently performs mainly at the Kašpar theater. He has appeared in episodic roles in the TV series Redakce, Poslední sezóna, Proč bychom se netopili, and in the films Swingtime, Tobruk, and Takový slušný člověk.

He has been involved in dubbing for a long time. In 2015, he received the František Filipovský Award for dubbing.

He played Jiří Markovič in the crime series Metoda Markovič: Hojer and Metoda Markovič: Straka. For this role, he won the 2024 Czech Lion Award in the category of Best Actor in a Leading Role in a Series.