David James Speirs (born December 15, 1984) is an Australian politician. He has been a Liberal member of the South Australian House of Assembly since the 2014 state election and leader of the Liberal Party since 19 April 2022. He represented Bright until 2018 and then Black following a redistribution of electoral boundaries. Speirs served as the Minister for Environment and Water in the Marshall Ministry between March 2018 and March 2022.