Thomas Birch, c. 5 June 1608 to 5 August 1678, was an English landowner, soldier and radical Puritan who fought for Parliament in the Wars of the Three Kingdoms, and sat in the House of Commons at various times between 1649 and 1658.

Part of a large Puritan family, many of whom also served in the Parliamentarian army, Birch helped secure Lancashire for Parliament during the First English Civil War.

[4] Little is known of his career prior to the outbreak of the First English Civil War in 1642; he had numerous relatives in the Manchester area, mostly Presbyterians who supported the Parliamentarian cause, including Colonel John Birch.

Although North-West England was largely Royalist, Manchester was a Parliamentarian stronghold; in June 1642, Birch was named Deputy Lieutenant of Lancashire and raised a regiment of infantry.

[5] When Derby besieged Manchester on 26 September, Birch was part of the garrison that held out until the Royalists retreated on 1 October, a victory that boosted Parliamentary morale in the area.

Birch was one of the few who retained their positions, replacing Wynn as MP for Liverpool in October 1649, and being appointed colonel of the Lancashire militia; for the next few years, he was the senior government officer in the region.

[2] When a Scottish army invaded England in 1651 during the Anglo-Scottish war (1650–1652), the Earl of Derby landed in Lancashire planning to link up with Charles II at Worcester.

Although the Earl escaped, he was taken prisoner after the Battle of Worcester in September, and executed; Birch and Robert Duckenfield were sent to secure the Isle of Man, which they completed by early November.

The latter was reluctantly called by Cromwell, largely to approve taxation for the army; along with Shuttleworth and Sir Richard Hoghton, both purged in 1648, Birch was one of the Lancashire MPs excluded from Parliament under Article VII of the 1653 Instrument of Government for opposing these measures.

[14] After Charles returned, Birch retired into private life; his past radicalism meant he was suspected of involvement in a 1663 republican conspiracy, but there was no evidence to support the claim.