Thomas Williams of Rushden Hall & Wanfield Lodge (c. 1794 – 2 December 1881) was a politician in the colony of South Australia, serving as a non-official acting member of the Legislative Council of South Australia from June 1843 to September 1843.
Williams was a son of Robert Williams of Wanfield Lodge (died 1803) and Jane Cunningham, whom he married in 1794. The Williams were an old family of Herringston, Dorset, with interests in the banking business.
Williams was at one time High Sheriff of Northamptonshire and a partner in the banking firm of Williams Deacon and Co. He was a major investor with the South Australian Company and closely associated with Lord John Russell, Gibbon Wakefield, and George Fife Angas.
Williams, his wife Catherine, née Codd, and much of their family emigrated on the Platina, arriving in South Australia in February 1839, and for a time they lived in "The Barn", in Wakefield Street, a rambling thatched wooden structure built in 1837, perhaps Adelaide's first permanent residence, whose previous tenants included H. B. T. Strangways, Lady Hindmarsh, then Hindmarsh's sons-in-law Milner Stephen and Alfred Miller Mundy. The place was destroyed by fire in May 1857.
Williams, with Governor Gawler and J. B. Hack had a "Special Survey" of Little Para farm land taken out in the Para Wirra area, and by him named "The Hermitage", his portion being 2,000 acres (810 ha). He fenced the property, and built a homestead where he lived, and as early as 1840 was growing wheat. He established a garden and vineyard, asserted to have been SA's first. To pay for this and for his children's education, he liquidated almost every one of his shares in the South Australian Company, coupled with an overdraft on his account with the Bank of South Australia of some ₤2,900.