Sushma entered the television industry after being encouraged by actor Vijay Kashi to try acting. She made her acting debut with director S. Narayan’s television serial Bhageerathi, where she played Veena. She later appeared in serials such as Swathi Muttu, Bidige Chandrama, and Yaava Janmada Maitri, in which she notably portrayed a triple role. However, her major breakthrough came with Guptagamini, where her performance as Bhavana earned her widespread popularity and the Karnataka Television Association Award for Best Actress.
She further strengthened her reputation through the Zee Kannada serial Sose Thanda Sowbhagya, where she portrayed Keerthi. The role earned her both the Zee Kannada Best Actress Award and the Zee Kutumba Award for Best Magalu in 2012. Over the years, she also expanded into television hosting, presenting shows such as Tarle Nan Maklu, Genes, and Mane Mane Mahalakshmi, becoming a familiar and respected television personality.
In 2022, Sushma returned to prominence with the lead role in Bhagyalakshmi on Colors Kannada. Her portrayal of Bhagya, a resilient woman navigating emotional struggles within a family, was widely appreciated by audiences and critics. The performance earned her Anubandha Awards for Best Mane Mechida Sose in 2023 and Best Actress in 2024. Known for her strong emotional performances, graceful personality, and long-standing contribution to Kannada television, Sushma K. Rao remains one of the respected actresses in Kannada entertainment.