| Theo Nicholls | |
| Senator for South Australia | |
| Term Start: | 1 July 1944 |
| Term End: | 30 June 1968 |
| Birth Date: | 1893 4, df=yes |
| Birth Place: | Wilmington, South Australia |
| Death Place: | Henley Beach, South Australia |
| Party: | Labor |
Theophilus Martin "Theo" Nicholls (21 August 1894 – 22 July 1977) was an Australian politician. Born in Wilmington, South Australia, he received a primary education before becoming a wharf labourer. He served in the military from 1915 to 1917 and was secretary of several unions including the Manufacturing Grocers' Employees Federation and the Wool and Basil Workers Federation.[1] He was active in a number of labour movement organisations, such as South Australian Trades and Labour Council, and was vice-president of the South Australian Labor Party. In 1943 he was elected to the Australian Senate as a Labor Senator for South Australia. He served as Chairman of Committees from 1946 to 1949.[2] Nicholls remained in the Senate until his retirement in 1967.
Nicholls died in 1977, aged 84.
His nephew, Martin Nicholls, was a Labor MP for Bonython 1963–1977.[3]