G Marimuthu is known for essaying key roles in projects like Tamil Rockerz, Vada Chennai and others. He had of late taken to acting and was seen in a number of movies and tele-serials. He began his journey as an assistant director. He was first seen in Ajith’s film Vaali in 1999 as a supporting actor. Marimuthu worked in several supporting roles including Yuddham Sei (2011), Kodi (2016), Bairavaa (2017), Kadaikutty Singam (2018), Sivaranjiniyum Innum Sila Pengalum (2021), and the Hindi film Atrangi Re (2021), among others. 

In 2008, Marimuthu made his directorial debut with Kannum Kannum featuring Prasanna and Udhayathara in lead roles. He also wrote the script, screenplay, and dialogues for the film. Not just this, Marimuthu was well-known and famous for his TV show Ethirneechal. He became a household name because of his character Aadhimuthu Gunasekaran' in the show.