Thomas Clarkson (28 March 1760 – 26 September 1846), is an English abolitionist, and a leading campaigner against the slave trade in the British Empire.

He helps found The Society for Effecting the Abolition of the Slave Trade and helps achieve passage of the Slave Trade Act of 1807, which ends British trade in slaves.

In his later years, Clarkson campaigns for the abolition of slavery worldwide.

In 1840, he is the key speaker at the Anti-Slavery Society (today known as Anti-Slavery International) conference in London, which campaigns to end slavery in other countries.