Harrison was the son of Richard Harrison of Hurst in Berkshire and his wife Elizabeth, daughter of Thomas Anton of Stratfield Saye in Hampshire, the Clerk of the Court of Wards and Liveries. His father died in 1587 and his mother remarried to Robert Marsh of Edmonton in Middlesex and Finchampstead in Berkshire.
He supported the Royalist side in the English Civil War. Harrison matriculated at Street Mary Hall, Oxford on 1 July 1603 aged 19. He was knighted on 31 August 1621.
He was elected Member of Parliament for Berkshire in 1624 and again in 1628 and sat until 1629 when King Charles decided to rule without parliament for eleven years.
He is said to have been created a baronet but the patent was lost. He was High Sheriff of Berkshire in 1636.
In April 1640, Harrison was elected Member of Parliament for Windsor in the Short Parliament. Harrison died at the age of 72 and was buried in Hurst parish church.
Short Parliament; Happy Parliament]
In 1621 Harrison was elected Member of Parliament (Member of Parliament) for Wootton Bassett.
