The Record Office, in Harold Street, will be open from 9.15am to 4.45 pm on the second Saturday of each month.
Information Services Manager Elizabeth Semper O’Keefe said: “Our open Saturdays are becoming increasingly popular and we are delighted to be able to extend them.
“This should help anyone who travels a long distance to use the archives and finds it difficult to visit during working hours,” she added.
Details of Saturday opening dates are available by telephone on (01432) 260750 and on the Record Office web pages at www.herefordshire.gov.uk/archives.