Spencer Compton, 2nd Earl of Northampton (May 1601 – 19 March 1643), styled Lord Compton from 1618 to 1630, was an English soldier and politician who sat in the House of Commons from 1621 to 1622. He became a peer by writ of acceleration in 1626 and by inheritance in 1630. He fought in the Royalist army and was killed in action at the Battle of Hopton Heath.
Northampton was the son of William Compton, 1st Earl of Northampton, and his wife Elizabeth, daughter and heir of Sir John Spencer, Lord Mayor of London. He was created a Knight of the Bath on 3 November 1616. In 1621 he was elected Member of Parliament for Ludlow. Also in 1621, he was appointed Master of the Robes to the Prince of Wales and attended the latter in the adventure to Spain in 1623. He warmly supported the king in the Scottish expeditions, at the same time giving his advice for the summoning of the parliament, which word of four syllables he declared was like the dew of heaven. In 1626, he became Baron Compton by writ of acceleration. In 1630 he inherited the Earldom on the death of his father in 1630 and assumed his duties as Lord Lieutenant of Gloucestershire and Lord Lieutenant of Warwickshire.
On the outbreak of the Civil War, Northampton was entrusted with the execution of the Commission of Array in Warwickshire. After varying success and failure in the Midlands, he fought at Edgehill and, after the king's return to Oxford, was given, in November 1642, the military supervision of Banbury and the neighbouring country. He was attacked in Banbury by the parliamentary forces on 22 December, but relieved by Prince Rupert of the Rhine the next day.