Colonel John Jones (c. 1597 – 17 October 1660) was a Welsh military leader, politician and one of the regicides of King Charles I.
A brother-in-law of Oliver Cromwell, Jones was born at Llanbedr in North Wales and is often surnamed Jones Maesygarnedd after the location of his Merionethshire estate. Jones spoke Welsh with his family. He was an avid Republican at a time when most of Wales was Royalist, and for this reason he was described by one of his contemporaries as "the most hated man in North Wales".
Jones was the son of Thomas ab John or Jones and Ellen, daughter of Robert Wynn ap Jevan. esq., of Taltreuddyn, was born at Maes-y-Garnedd (or Maesygarnedd) in Merionethshire.
During the civil war Jones served in the parliamentary forces in Wales, and was described as a colonel in 1646, while negotiating the surrender of Anglesey in June 1646. In 1648 he helped to suppress Sir John Owen's rising, was thanked by the House of Commons for his share in the reconquest of Anglesey, and was voted £2,000 on account of his arrears of pay. He was returned to the Long Parliament in about 1647 for Merionethshire.
Jones was selected as one of the judges of King Charles I, and attended the trial with great regularity up to the day he signed the King's death-warrant. After execution of the King, Jones was elected a member of the first two Councils of State of the Commonwealth
In July 1650 Jones was voted one of the commissioners to assist the lord deputy in the government of Ireland, and was reappointed for two years longer on 24 August 1652. His colleague Edmund Ludlow describes him as "discharging his trust with great diligence, ability, and integrity, in providing for the happiness of that country, and bringing to justice those who had been concerned in the murders of English Protestants".