Sir Thomas Buckler Lethbridge, 2nd Baronet (1778–1849) of Sandhill Park in the parish of Bishops Lydeard and of Royal Crescent,^{[lower-roman 1]} in Bath, ^[3] both in Somerset, was an English politician and soldier.

He was born in 1778, the son and heir of Sir John Lethbridge, 1st Baronet (d.1815) of Sandhill Park, whose title had been created in 1804 for his help in paying the Prince Regent's gambling debts.^[5] He was disinherited by his father, but they were later reconciled, but the will was destroyed shortly before his father died in 1815.^[3] His mother Dorothy died in 1831.^[6] His sisters were Dorothea Lethbridge who in 1800 married Henry Powell Collins, a Member of Parliament for Taunton and Frances Lethbridge, who in 1804 married Sir Charles Henry Rich, 2nd Baronet.^[6] Through his father's affair with Mary Jane Clairmont, he had an unacknowledged half-sister, Claire Clairmont, mother of Lord Byron's daughter Allegra.

Lethbridge was educated at Oxford.^[3] In May 1806 Lethbridge became one of two MPs for Somerset.^[3] As a rural squire, he was a staunch defender of the Corn Laws in their last years before repeal and was opposed to the Anti-Corn Law League.^[7] Considered a High Tory, he resigned his seat in 1830, two years before the Great Reform Act.^[8]

Lethbridge married twice:^[13]

• Firstly, in 1796, to Jacintha Catherine Hesketh (d.1801), a member of the Hesketh family of Rufford Hall in Lancashire, by whom he had two children, a son and a daughter:
  • John Hesketh Lethbridge, 3rd Baronet, eldest son and heir, who in 1817 married Harriet Rebecca Mytton, a daughter of John Mytton.^[14]
  • Jacinta ("Jessy") Dorothea Lethbridge, who in 1818 married Ambrose Goddard (1779–1854), MP, of Swindon in Wiltshire, and was the mother of Ambrose Lethbridge Goddard, and of Emma Caroline Goddard who married Greville Phillimore.^{[15][16][17][18]}
• Secondly, in 1803, he married Anne Goddard, a daughter Ambrose Goddard, of Swindon in Wiltshire, by whom he had two sons and four daughters:
  • Ambrose Goddard Lethbridge (died 1875), a barrister and Fellow of All Souls College, Oxford.^[15][19]
  • Thomas Prowse Lethbridge, who in 1834 married Isabella Escott, a daughter of Rev. Thomas Sweet Escott of Hartrow.^[15]
  • Anna Maria Lethbridge^[15]
  • Lucy Sarah Lethbridge, who in 1831 married Hugh Fitzroy, son of the Rev. Lord Henry Fitzroy.^[15]
  • Emma Dorothea Lethbridge, who in 1826 married Sir Francis Dugdale Astley, 2nd Baronet,^[15] the son of Sir John Astley, 1st Baronet, a Member of Parliament.^[20]
  • Frances Margaret Lethbridge.^[15]

He died in 1849. An obituary notes the death of Sir Thomas Buckler Lethbridge, describing him as for many years a prominent Member of the House of Commons on the Conservative side.^[21] He was succeeded by his eldest son Sir John Hesketh Lethbridge, 3rd Baronet.