US President Donald Trump’s youngest daughter, Tiffany, is engaged to be married.

The 27-year-old recent Georgetown law school graduate announced her good news on Instagram on Tuesday, her father’s final full day in office.

She shared a photograph of herself and fiance Michael Boulos posing on the West Wing colonnade at the White House.

Tiffany Trump says her father Donald Trump shows her “love and guidance”. Photo: Instagram

“It has been an honour to celebrate many milestones, historic occasions and create memories with my family here at the White House, none more special than my engagement to my amazing fiance Michael!” Tiffany Trump wrote.

“Feeling blessed and excited for the next chapter!”

Donald Trump and Marla Maples together with daughter Tiffany in 1995 in New York. Photo: Getty

Tiffany Trump with her mother, actress Marla Maples. Photo: Instagram

Boulos, a 23-year-old business executive, also shared the photograph on his Instagram account.

“Got engaged to the love of my life! Looking forward to our next chapter together,” he wrote.

Tiffany Trump is the president’s daughter with Marla Maples, his second ex-wife.

-AAP