Pääru Oja (born May 16, 1989) is an Estonian stage, film, voice, and television actor.

Pääru Oja was born in Tallinn, the youngest of two sons. His father is actor Tõnu Oja and his older brother is Estonian Theatre Festival CEO and theatre manager Kaarel Oja, who is married to actress Ursula Ratasepp. His uncle is actor, director and theatre instructor Rein Oja. He attended primary and secondary schools in Tallinn before being accepted to the Estonian Academy of Music and Theatre in Tallinn, where he graduated from in 2012 under course supervisor Elmo Nüganen. Oja's diploma roles included Father of Toulon in Peter Barnes' Red Noses (2010), Joseph Wykowski in Neil Simon's Biloxi Blues, and Argante in Molière's The Imaginary Invalid (2011). Among his graduating classmates were: Henrik Kalmet, Karl-Andreas Kalmet, Priit Pius, Märt Pius, Liis Lass, Piret Krumm, Maiken Schmidt, and Kaspar Velberg.