Frederick Thellusson, 4th Baron Rendlesham DL (6 January 1798 – 6 April 1852), was a British Conservative Party politician.

[1] Among his siblings were John Thellusson, 2nd Baron Rendlesham (who died without male issue),[2] Hon.

George Thellusson (a Lieutenant in the 11th Dragoons who was killed in action at the Battle of Vitoria),[3] Hon.

[4][5] William Thellusson, 3rd Baron Rendlesham (the Vicar at Aldenham who died without male issue),[2] Hon.

He was instead elected to the House of Commons as Member of Parliament (MP) for Suffolk East at a by-election in 1843, a seat he held until his death nine years later.