The 57-year-old has given formal notice to wed Elliott Spencer, 27, at a register office in Dereham, Norfolk, near where he grew up.
According to documents on display in Norwich, the wedding will take place in the Breckland Business Centre which houses the register office.
This is a non-descript, red-brick building off the town’s high street. No date has been set for the ceremony.
According to the Norfolk County Council website, the ceremony room is the “outstanding feature” of the building.
It adds: “Decorated in a modern style, in shades of turquoise, lilac and purple, there is seating for 40 people.
“The ceremony room overlooks the Queen Mother’s Garden, which is the ideal setting for photographs.”
On the paperwork, Fry gives his occupation as actor while Mr Spencer is listed as a writer. Both say they are currently living in Norfolk.
Fry’s personal assistant said the wedding was a private matter, adding: “Stephen Fry is very happy and proud to say that he has set the wheels in motion for a wedding some time in the future but no date has been set due to a busy work schedule.”
Writing on Twitter, the presenter said: “Oh. It looks as though a certain cat is out of a certain bag.
“I’m very, very happy of course but had hoped for a private wedding. Fat chance!”
He said “adorable tweets” from fans had left him “close to sobbing”, adding: “Thank you all SO much for your kind congratulations. Deeply touched xxx.”
Fry first found fame as part of a double act with Hugh Laurie after the pair met at university.
They appeared in their own long-running show as well as in the Blackadder series and a TV adaptation of the Jeeves and Wooster novels.
He has also produced a string of documentaries, novels and memoirs and hosts the panel show QI.
There have also been occasional film and theatre roles, including a notably short-lived appearance in the West End play Cell Mates which he quit after three days, pleading stage fright.
He later said the incident was an early public example of his struggles with depression.
Fry, who grew up in Norfolk, is an enthusiastic fan of Norwich City football club and joined the board of directors at Carrow Road in 2010.
He has spoken openly about his struggles with drug abuse and depression, has largely kept his love life private although he reportedly separated from a long-term partner five years ago.
He has also spoken openly about a suicide attempt in 2012 while filming a documentary about homophobia around the world.