Lewis Watson, 1st Earl of Rockingham (29 December 1655 – 19 March 1724) was an English peer and politician.
Rockingham was the eldest son of Edward Watson, 2nd Baron Rockingham and his wife, the former Lady Anne Wentworth, daughter of Thomas Wentworth, 1st Earl of Strafford. In 1677, he married Lady Catherine Sondes, a daughter of George Sondes, 1st Earl of Feversham. They had five surviving children:
From 1681–85, Watson was Whig Member of Parliament for Canterbury and for Higham Ferrers briefly in 1689, before having to leave the Commons on inheriting his father's barony that year.
Lord Rockingham was Master of the Buckhounds from 1703–05, Custos Rotulorum and Lord Lieutenant of Kent from 1705–24, Vice-Admiral of Kent in 1705 and Deputy Warden of the Cinque Ports from 1705–08. In 1714, he was created Earl of Rockingham and on his death in 1724, his titles passed to his grandson, Lewis.