Major-General Sir Henry Frederick Ponsonby (10 December 1825 – 21 November 1895) was a British soldier and royal court official who served as Queen Victoria's Private Secretary.

Born in Corfu, he was the son of Major-General Sir Frederick Ponsonby, an Anglo-Irish nobleman who was a senior commander in the British Army.

On 2 August 1860 he became colonel, and in 1862, after the death of the prince, he was sent to Canada in command of a battalion of the Grenadier Guards which was stationed in the colony during the American Civil War.

The couple had five children:[1][2] Lady Caroline Lamb (née Ponsonby), his father's sister, had been married to Lord Melbourne, who was prime minister to Queen Victoria during her first years on the throne.

His letters bore addresses appearing as doodled signposts in snowstorms or as huge envelopes shouldered by tiny people.