Sudhir Kumar belonged to a Maharashtrian family from Lalbaug, Parel, Mumbai. He completed his SSC education at Aryabhattam School. His maternal uncle, Prabhakar, worked as the chief make-up artist at V. Shantaram's Rajkamal Kalamandir, which helped give Sudhir an early connection with the film industry.
He made his film debut with Sant Gyaneshwar (1964). In the same year, he appeared in Dosti, directed by Satyen Bose and produced by Tarachand Barjatya. Sudhir played Mohan, a blind singer, alongside Sushil Kumar. Dosti became one of the notable successes of 1964 and won six Filmfare Awards.
Following Dosti, Sudhir Kumar appeared in films including Laadla (1966), Mera Munna (1967), Ghar Chi Rani (1968), Jeene Ki Raah (1969), Janki (1979), Mera Naam Raja (1978) and Son of Andaata (1987). However, his acting career did not develop as expected, and he was largely away from the film industry by the end of the 1960s.
Sudhir Kumar later remained away from public life. There were various rumours surrounding his disappearance from the film world, but these were subsequently contradicted by information from his family. According to Cinemaazi, he died after suffering from cancer. IMDb records his death as 12 January 1993 in Mumbai.