Thomas Willoughby, 11th Baron Willoughby of Parham (c.1602–1691/92) was an English peer of the House of Lords. He was born in about 1602, son of Sir Thomas Willoughby and Mary Thornhaugh (Thornley), and grandson of Charles Willoughby, 2nd Baron Willoughby of Parham and Lady Margaret Clinton. He married Eleanor Whittle, daughter of Hugh and Mary Whittle, of Horwich on 22 February 1639 (or 1640). After marriage they lived at Old Lord's Farm in Horwich, the area is still known as 'Old Lords Estate'. They had two sons and three daughters, Hugh, the eldest son and Francis who in 1696 married Eleanor Rothwell of Haigh. Their daughters were Mary who married Samuel Greenhalgh of Adlington, Sarah and Abigail. Eleanor died aged 67 in 1665.
Thomas was a staunch puritan and is closely associated with dissenting religious bodies. During the English Civil War, he was a major and fought on the side of the Parliamentarians. He saw action in the first and second battles at Middlewich in 1643, and at the Bolton Massacre in 1644. He was a governor of Rivington Grammar School during the Commonwealth and after Restoration from 1650 until 1691. The school lacked income between 1650 and 1660 so Thomas travelled to London, York and Durham for affidavits and trials and secured the rental income for the school. In the school's records he is noted as Gentleman of Horwich. He served as Chairman of Governors in 1651, 1653–54, 1653, 1670, 1676 and 1683.