John Fenwick (14 January 1602 to 2 July 1644) was a Member of Parliament from Northumberland, killed serving in the Royalist army during the First English Civil War.

John Fenwick was the only son of Sir John Fenwick, 1st Baronet of Wallington Hall, Northumberland, and his first wife Katherine (1584-1616), sister to Sir Henry Slingsby, executed in 1658 for his part in a Royalist conspiracy.

[1] He married Mary, daughter of Sir George Selby, of Whitehouse, County Durham.

[2] Fenwick matriculated from Trinity College, Cambridge at Easter 1628.

[3] In early 1644, he raised a troop of dragoons for the Royalist Northern Army; [4] and was excluded from Parliament on 22 January 1644.