Sir Thomas Rainsford Bavin, KCMG, KC (5 May 1874 – 31 August 1941) was an Australian lawyer and politician who served as Premier of New South Wales from 1927 to 1930.

His predecessor Jack Lang and the Australian Labor Party (ALP) defeated his government after a single term at the 1930 state election.

[3] Called to the New South Wales Bar in 1897, Bavin became involved in the cause of Australian Federation, unsuccessfully standing for the Legislative Assembly seat of Canterbury on a pro-Federation platform in 1898.

[5] In 1901, after a chance encounter at an Albury railway station, Barton appointed him as his private secretary in place of Atlee Hunt, who had received a promotion.

[3] Bavin returned to the Bar in 1904 but found briefs scarce and so began writing op-ed pieces for Sydney newspapers, and, along with Deakin, serve as the Australian correspondent for the London Morning Post from 1907 to 1911.

[4] Bavin's attempts to enter federal parliament were thwarted, thrice losing Commonwealth Liberal Party pre-selection, due partly to his support for greater social welfare expenditure.

Following an agreement by the Nationalist and Country parties not to stand candidates against each other, the coalition won the 1927 election and Bavin became Premier and Treasurer on 18 October 1927.