Samuel Tertius Galton (23 March 1783 – 23 October 1844) was a British businessman and scientist.

Samuel Tertius, though less distinguished, was not an exception to the rule of scientific endeavour in his family.

Mary Gartside mentions his work in her book An Essay on a New Theory of Colour in 1808.

[3] Though fascinated by economics (he wrote papers on the subject), Samuel preferred to be less 'hands-on' in the running of the business than his father and spent much of his time living off the revenue of his considerable estate.

On 30 March 1807, he married Violetta (Francis Anne Viollette) Darwin, one of the fourteen children of his father's old colleague and fellow Lunar Society member Erasmus Darwin.