They want family members to claim the portraits of former residents at the home.
It is thought the pictures were painted between 1940 and 1980 at Clifton House in North Queen Street.
It is believed the artist was Thomas Everard Spence. He was the former president of the Belfast Charitable Society.
The home's owners said records of family members were no longer available.
They hope that people will recognise relatives and come forward. The pictures can be viewed on the home's website and on Facebook.
The owners of a north Belfast residential home have discovered nearly 30 paintings in the attic.