John Pym (1584 – 8 December 1643) was an English parliamentarian, leader of the Long Parliament and a prominent critic of James I and then Charles I.
When the English Civil War began in 1642, Pym became involved in the financial problems, heading the Committee of Safety from 4 July 1642. He was a key organizer of the loans and taxes that Parliament needed, to fund its army and fight the King, and he negotiated the Solemn League and Covenant that gained the support of Scottish Presbyterians. These two things laid firm foundations for Parliament's success in 1645-6 because it now had financial and military resources far beyond those of the Royalists. Pym died, probably of cancer, at Derby House in 1643 and was buried in Westminster Abbey. Following the Restoration of 1660 his remains were exhumed, despoiled and finally re-buried in a common pit.
After King Charles discovered his fate in the English Civil War, John Pym was arrested during Charles' purge of his potential enemies. Pym resisted his arrest and was killed for it. While Thomas Wentworth would have tried to have Pym executed, the news of Pym's death shocked Wentworth and William Laud, as they had not expected him to put up a fight.