Kumar began acting during his time as a college-going student in Tiptur, Karnataka, along with his theatre groups like Geleyarabalaga, Mungaru Hudugaru and Abhinaya Theatre Group, under the guidance of Nataraj Huliyar. Later, he started his training as an actor at Ninasam. Working in theatre during the time, he was chosen by Girish Kasaravalli to play a pivotal role in his television soap Gruhabhanga in 2000.[2] In the soap Moodala Mane, Kumar played a supportive colleague to the daughter of the protagonist. In Preethi Illada Mele, he played the eldest son of a judge (played by Anant Nag).[citation needed]
In Hejjegalu (2013), Kumar played Kodanda, a gambling addict who squanders money taken on loan, being tried to reform by his young daughter.[4] The performance won him the Karnataka State Film Award for Best Supporting Actor.[5] He received praise for his portrayal of Shivappa, a scavenger in Amaraavati (2017).[6][7] In Urvi (2017), based on the menace of child trafficking, he played Devarugunda, an influential man who kidnaps women, rapes them and forces them into prostitution. Archana Nathan of The Hindu wrote, "Achutha Kumar performs well, but one wishes that his character had been given some more depth and background."[8]
In the 2022 drama film, Kantara, Kumar played a treacherous feudal lord Devendra Suttooru, scheming to snatch land from the tribal community after appearing to help them. Deccan Herald wrote, "... given how brilliant Achyuth is, the character's sudden switch in the trait is made invisible by his effortless transformation."[9]The New Indian Express termed his performance "powerful".[10]
^Suresh, Sunayana (10 February 2017). "Amaravathi Movie Review". The Times of India. Archived from the original on 13 February 2017. Retrieved 5 April 2017.