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 , 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.