The plaque, sponsored by the Royal Hospital Nurses League, will later be fitted to the front of the Royal Hospital, which is currently being redeveloped by WHG into apartments.
The Royal Hospital was opened in 1849 and closed in June 1997 with services being transferred out of the town centre to New Cross Hospital.
Former Nurse and Nurse Tutor at The Royal Hospital, Roy Stallard, from Penn – who is now a hospital historian – was president of the Royal Hospital Nurses League which funded the plaque.
Mr Stallard, aged 89, first started work at the Royal Hospital as a Nurse in 1954 and later became a classroom tutor.
He said: “We have been waiting several years to reach this point. Due to the complexity of the development, planning approval needed for a listed building and, not least, safe access to the site, the grand unveiling was delayed so to get to this point now is fantastic.
“When the league closed, we had a pot of money left so we decided to allocate it out to different causes including donating six radiology monitors to Deanesly Centre at New Cross and also spending £1,000 on a blue plaque to mark the vital contributions of staff at the Royal over many years.
“I think the plaque is a fantastic tribute to everyone who worked at the hospital. It will be a wonderful reminder of all the hard work and brilliant care which was delivered there.”
The plaque was unveiled by The Royal Wolverhampton NHS Trust Chaplain Reverend Angela Gemmer-Snell after she gave a blessing and Rob Marris, former Labour MP for Wolverhampton South West.
The project was organised by The Wolverhampton Society which has been adding plaques to sites around the city since 1983 and is run by volunteers.