Ernst II Leopold (15 June 1684 – 29 November 1749) was Landgrave of Hesse-Rotenburg from 1725 until his death.

[1] Born in Langenschwalbach, into the collateral branch of the House of Hesse, he was a son of Landgrave William, Landgrave of Hesse-Rotenburg and his wife, Countess Maria Anna of Löwenstein-Wertheim-Rochefort (1652–1688).

He married his first cousin, Countess Eleonore of Löwenstein-Wertheim-Rochefort (1686–1753), in Frankfurt, on 9 November 1704.

She was daughter of Maximilian Karl Albert, Prince of Löwenstein-Wertheim-Rochefort and his wife, Countess Maria Polyxena Khuen of Belasi and Lichtenberg (1658–1712).

They had ten children: Through his eldest daughter, his present descendants include the claimant Duke of Parma; the pretending King of the Two Sicilies and the reigning Grand Duke of Luxembourg.