The former convalescent home was announced as Grade 2 listed by the Department for Digital, Culture, Media and Sport on the advice of Historic England.
Designed by architect William Henry Ansell, it was built by the National Deposit Friendly Society as a memorial to members who fell in World War I.
It was opened in 1926 by Queen Victoria's granddaughter, Princess Marie Louise, accompanied by Neville Chamberlain who was then the Health Minister.
In more recent years since being owned by East Lindsey District Council it has been used as council offices and headquarters of Visit Lincs Coast (BID).
The building received listed status along with the Crow Stone at Chalkwell Beach in Southend, Hythe Pier in Hampshire, The Coronation Boathouse at Bantham Quay in Devon, Middle and Lower Walk Colonnades and the Promenade Shelters, both in Blackpool.
Caroline Dinenage MP (Con), heritage minister, said: "I am delighted that these six seaside heritage sites have been listed.
"Our magnificent seaside towns have been must-visit destinations for hundreds of years and many of us have rediscovered just how much they have to offer this summer.
"It is absolutely right that these sites will be recognised and protected."
Former councillor John Byford commented: "This has been long overdue
"Skegness has lost so many important buildings over the years. It’s important to save the remaining."
Paul Sutton commented on a post on social media by Mr Byford that the building doesn't belong to Skegness now and said it has "30 years of neglect to be dealt with".
However, Skegness' Coun Danny Brookes said it was unlikely ELDC would do anything with it.
He said: "The building is quite old and it needs a lot of work doing on it so I think it's going to be very expensive to do anything with it now.
"I'm not sure it's really a historic building - it used to be an old care home and I would like to see it smartened up.
"They can't do a lot with it now though without special permission which is going to be expensive so I think it's going to go further and further downhill."