Devendra Singh has been in politics from the early 1950s heading the Badliyas village Panchayat. He held the position of Sarpanch for a record 12 years from 1952. Later he went on to become the Pradhan of Panchayat Samiti, Kotri.
A Congressman, Devendra Singh was elected to Rajasthan Assembly for the first time in 1980. Ever since he has been elected to the assembly thrice. In 1982, he was appointed a deputy minister.
He was elected as the Deputy Speaker, Rajasthan Legislative Assembly on March 26, 1999.