The Duke met residents, their families and staff at Osborne House, in Union Lane before unveiling a plaque to mark its official opening.
The first residents moved into the home just before Christmas enjoying five star facilities and the highest standards of care.
Operated by Crown Care, Osborne House has 74 bedrooms with ensuite shower facilities as well as a library, café and IT suite and will employ around 100 staff once at full capacity.
Wendy Conn, Crown Care’s managing director of healthcare, said: “We are very proud of Osborne House and absolutely delighted to welcome HRH The Duke of Gloucester to open it and to meet some of the residents.
“The facilities are fantastic. It has the feel of home-from home and has been designed to give the people who to live here or stay with us, the comfort and care they deserve.”
Osborne House also has a specialist unit providing a comprehensive physical recovery programme for adults with complex care needs.