Thomas Pemberton Leigh, 1st Baron Kingsdown PC, KC (11 February 1793 – 7 October 1867), was a British barrister, judge and politician.

Having turned down the post of Lord High Chancellor of Great Britain in 1858, he was the same year elevated to the peerage as Baron Kingsdown.

[1] Pemberton Leigh's judgments, more particularly in prize cases, of which he took especial charge, are remarkable not only for legal precision and accuracy, but for their form and expression.

The arbitration, as instructed by the Crown, was based on legal argument and documentation which led to the Cornwall Submarine Mines Act of 1858.

Lord Kingsdown died at his seat, Torry Hill, near Sittingbourne, Kent, on 7 October 1867, aged 74.

[citation needed] He wrote Recollections of Life at the Bar and in Parliament (privately printed for friends, 1868); The Times (8 October 1867).