He said: "I had the absolute honour of performing for and meeting the Duke and Duchess of Cambridge & the Duke and Duchess of Sussex for the annual @KensingtonRoyal Royal Foundation dinner. Thanks to the talented @thatsingingbird from @wearefulleffect for joining me for my last song."
In one image, Tom looks relaxed as he chatted to Harry and Meghan alongside host for the evening, television presenter Anita Rani.
He later posed with Anita, William and Kate inside the event, before he was pictured in discussion with the Duke of Cambridge, all of which he made sure to post on his social media pages.
Kate, who has recently appeared to be recycling many of her favourite gowns, wore an elegant red Preen dress she had previously donned during her tour of Canada.
Meanwhile pregnant Meghan looked radiant in a strapless navy Roland Mouret gown in the Aldrich style, which appeared to have been customised with a fuller skirt.
She wore with her $2080 dress a pair of Birk's Snowflake earrings, and carried a navy UFO clutch which she previously toted at another event.
The Royal Foundation they were attending in honour of was set up in 2009 by the two Dukes and now Kate and Meghan have joined their husbands as patrons of the foundation.
The foundation aids the royals in completing charity work surrounding mental health, wildlife and conservation, young people and the armed forces.
