Joseph Maynard (1639 – 25 October 1689) was an English politician who sat in the House of Commons from 1665 to 1679.
Maynard was the son of Sir John Maynard, MP, by his first wife Elizabeth Henley daughter of Andrew Henley of Taunton, Somerset and was baptised on 15 December 1639.
He was a student of Middle Temple in 1663 but was never called to the bar as he came "much short of his father's intellectual parts".
He did not stand for parliament again as his father preferred to nominate more eminent representatives for the family borough.
Maynard married twice: He died in his father's lifetime at the age of about 50 and was buried at Ealing.