A Clerk of the Petty Bag was a clerk in the former Petty Bag office of the English Court of Chancery.
The Petty Bag office dealt with common-law issues in the Court of Chancery and dated from as early as the 14th century, declining in importance towards the end of the 17th century.
Its responsibilities were various, including dealing with suits against solicitors or attorneys and officers of the court itself, issuing writs for Parliamentary elections and the elections of bishops, summonses to Parliament and the enrolling of solicitors of the court itself.
The name of the office stemmed from the practice of keeping records in small paper bags.
The single remaining clerk was transferred to the Supreme Court of Judicature in 1875, and the post finally abolished in 1889.