Joseph-Marie Nielly (1751–1833) was a French naval officer and admiral. Nielly was born and died in Brest. He began his career aged seven aboard the Formidable, and was wounded at the Battle of Quiberon Bay, on 20 November 1759. He sailed in the Caribbean until 1769, when he joined the merchant navy. A resolute Republican, Nielly had his crew sign a manifesto supporting the Constitution of the French First Republic, and sent it to the National Convention. In November 1793, he was promoted to contre-amiral. At the Action of 6 November 1794, Nielly's division captured HMS Alexander.