The opening ceremony, which took place on Friday, April 11, marks the completion of eight years of work to create the centre which houses the 100,000-strong county museum collections.
Funding for the project has come from The Heritage Lottery Fund (HLF) - £1.2 million, and Herefordshire Council, with phase three costing £1.8 million.
This means that the items in the collections are now accessible to the public.
Work to convert the former telephone exchange building was been carried out in three phases.
Phase one involved the purchase of the site and creation of one collection store.
Phase two involved the conversion of the entire building to museum use and moving collections from a number of sites across the county.
Phase three was a new extension to create the final collection facilities, the learning room and public exhibition area.
The temporary exhibition in the atrium is now open Monday to Fridays, 10am to 4pm (except for bank holidays and the day of the official opening),
Schools are now using the centre for educational sessions. There have been a series of evening and weekend lectures and workshops and four open days so far, with a Japanese-themed open day on March 27 attracting more than 160 visitors. A full programme of events is in place for the coming year.
With the centre fully operational, the service has also just received the good news that the site has achieved Full Accreditation from the national standard for museums and galleries, moving on from the Provisional Status awarded last summer
Collections are currently being moved into their final locations with cataloguing, sorting and re-housing underway with the biological, geological, rolled textiles and art collections. Our volunteer teams are playing an important role in this work.
HRH met some of the staff and volunteers and was shown the type of work they are involved with. The permanent exhibition is currently being designed and will be in place in the summer.
Anne Jenkins, Regional Manager for HLF West Midlands, said:
"We are delighted to see Friar Street officially open and that these important collections fully accessible to the community for the first time. The Heritage Lottery Fund wishes the museum every success for the future."
Cllr Adrian Blackshaw, Herefordshire Council's cabinet member for economic development and community services, said:
"The facilities in the resource centre are first class and it mean that the items from Herefordshire's heritage at the centre are now kept in a state-of-the art facility.
It's taken a number of years to get where we are, but I'm sure anyone who looks round the centre will realise what a wonderful facility it is. We're extremely grateful to the Heritage Lottery Fund for their support and I hope local people will now take advantage of the facilities to explore their own heritage in Herefordshire."