Sir Thomas Rumbold, 1st Baronet (15 January 1736 – 11 November 1791) was a British administrator in India and politician who sat in the House of Commons between 1770 and 1790.

In 1769 Rumbold returned to Britain with a large fortune, knowing the importance of parliamentary influence in the internal politics of the East India Company.

He received the majority of the votes, but so many were disallowed by the returning officer on grounds of bribery that he was defeated; however, on petition the result was overturned and Rumbold declared duly elected.

The Commons Committee not only overturned the election result, but ordered that Sykes, Rumbold, and a long list of other inhabitants of the town should be prosecuted by the Attorney General for bribery and perjury.

He was created first baronet of Wood Hall (referring to Woodhall Park, his Hertfordshire estate) on 27 March 1779.However, Sir Thomas was also responsible for negotiations with Haidar Ali, and was unable to dissuade him from invading the Carnatic or to prevent him from succeeding.

He resigned the governorship for reasons of ill health in 1780, and was subsequently dismissed from the service of the company by the court of directors, who held him responsible for the Carnatic invasion and the Second Anglo-Mysore War.

A parliamentary enquiry was also imminent, and he was anxious to be in the Commons to defend himself, but he had once more been unseated for electoral corruption (having won the 1780 election at Shaftesbury in his absence the result had been overturned again), and had to buy himself a seat at Yarmouth (Isle of Wight).