Hilda Frances Mason was born in Ipswich, Suffolk, England on 17 June 1879 and was the daughter of Frank William Mason (1848–1927), a cement and timber merchant. It is not know where or with whom she trained as an architect. She was elected an Associate of the Royal Institute of British Architects (ARIBA) in 1925.
She worked primarily in Suffolk and was known particularly for her use of reinforced concrete. Her most notable works were St Andrew's Church in Felixstowe, designed in collaboration with Raymond Erith (1904-1973), and built between 1929 and 1931, and Kings Knoll in Woodbridge, Suffolk, a house in a modified version of the International Style, which she built for herself in 1933. Both these buildings are now Grade II* listed.
In addition to her work as an architect, Mason was a watercolour painter and from 1907 to 1939 was a member of the Ipswich Art Club with whom she exhibited. She also designed at least one poster, 'Castle Combe, near Bath', which was shown at the Ipswich Art Club in 1925.
Mason's address was given as The Priory, Wolsey Street, Ipswich, Suffolk in 1881 in 1891; North Cliffe, Maybush Lane, Felixstowe, Suffolk in 1901 and 1926; North Cottage, Felixstowe, Suffolk in 1930; and Kings Knoll, Woodbridge, Suffolk in 1933 and 1955. She died in Ipswich, Suffolk on 14 April 1955 Her obituary appeared in The Builder vol.188, 5 May 1955 p.761