The group already operates a five star hotel near the Waterfront Hall. It is thought that it is looking for a site for its budget Hampton by Hilton brand.
The Hampton brand has been expanding rapidly across the UK and Europe over the last two years.
An industry source suggested the group could be involved with a recently filed planning application for Hope Street.
A Hilton spokesman said: "I can confirm that Belfast is a destination which has attracted our interest and we continue to review potential sites to increase our presence in the city.
"We are unable to comment further at this stage."
The Hilton Hotel group has said it is looking at development sites in Belfast with a view to expansion.