Sir George Colebrooke, 2nd Baronet (14 June 1729 – 5 August 1809), of Gatton in Surrey, was an English merchant banker, chairman of the East India Company and Member of Parliament, who bankrupted himself through unwise speculations.
Colebrooke was the third son of James Colebrooke, a London banker, and was educated at Leiden University. After the death of his father and an older brother he was left in sole charge of the family bank in Threadneedle Street, and invested some of his wealth in buying up control of the borough of Arundel in Sussex, where the family lived. Arundel was not a classic pocket borough, where the power to return MPs was literally tied to property rights that could be freely bought and sold, but a thoroughly corrupt one where bribery was routine and where maintaining influence of the elections required constant expenditure. Nevertheless, Colebrooke kept control for twenty years, sitting himself as its MP from 1754 to 1774 and for most of the period being able to choose also who held the other seat. Meanwhile, his brother, James had bought control of one seat in another rotten borough, Gatton in Surrey, for £23,000, and was also sitting in Parliament. Both brothers were at first Opposition Whigs, but switched support to the Duke of Newcastle's government and were rewarded in 1759 with the creation of a baronetcy for James (who had daughters but no son) and a special remainder of the baronetcy to George. When James died in 1761, George inherited both the baronetcy and the Lordship of the Manor at Gatton with its guaranteed control of one of the parliamentary seats there.