John Byron, 1st Baron Byron (1599, Newstead, Nottinghamshire – 23 August 1652) was an English Royalist, nobleman, politician, knight, and supporter of Charles I during the English Civil War.
John Byron was the son of Sir John Byron (died 1623). He was educated at Trinity College, Cambridge. He succeeded his father in 1625.
He was elected as MP for Nottingham in 1624 and 1626. He was knighted (KB) in 1626 and was then elected as knight of the shire (MP) for Nottinghamshire in 1628. He also served as High Sheriff of Nottinghamshire for 1634 and then as Lieutenant of the Tower of London, from December 1641 to February 1642.
When the Civil War started, he joined the king at York. He was engaged on the Royalists' cause throughout the Civil Wars and afterwards. After Byron distinguished himself at the First Battle of Newbury King Charles created him Baron Byron in October 1643 and made him commander of the Royalist forces in Lancashire and Cheshire. However he was defeated at the Battle of Nantwich in 1644 and forced to withdraw to Chester. He then marched with Prince Rupert’s forces into Yorkshire and commanded the royalist right flank at the Battle of Marston Moor in July 1644, but after his troops were routed by numerically superior parliamentarian forces he retreated to Carnarvon and resigned his command.
Lord Byron died in 1652, childless, in exile in Paris, and was succeeded by his next eldest brother Richard Byron, 2nd Baron Byron (born 1606).