Geronimo Inns has bought the freehold for the Clarence in Whitehall for just under £4m from private investors.
The pub company originally took on the leasehold of the site, where Sir Winston Churchill was once reputed to be a regular, in 2009.
The deal was brokered by licensed leisure specialists AG&G.
"The Clarence's owner us let us know that the freehold was available, so we set about finding a suitable buyer," said Anthony Alder of AG&G.
"It's not often that such a landmark central London pub comes on to the market, so it was a pleasure to be involved."
The Clarence is an imposing corner property dating from 1862. It is has four upper floors over a ground floor trading area and storage basement. It has been run as a high-quality traditional pub, offering classic food and real ales, and was fully refurbished in early 2007.
By Neil Gerrard
E-mail your comments to Neil Gerrard here.
If you have something to say on this story or anything else join the debate at Table Talk - Caterer's new networking forum. Go to www.caterersearch.com/tabletalk
Looking for a new job? Find your next job here with Caterersearch.com jobs