Gladwin was born at 44 Tatton Street in the Ordsall district of Salford, Lancashire, the son of Joseph and Elizabeth (née Dooley) Gladwin. He was baptised on 28 January 1906 at Mount Carmel Roman Catholic Church, Ordsall, and educated at the parish school. He married Lily Anne Wynne on 30 December 1933 at Mount Carmel Church. Gladwin was appointed a Papal Knight (of the Order of St. Gregory the Great) for his charity work.
Gladwin worked as a 'feed' for Dave Morris (comedian) for twelve years beginning in 1950. He appeared in British television since the 1960s, some notable appearances include Z-Cars, Dixon of Dock Green and The Artful Dodger. He also had a recurring role in Coronation Street between 1961 and 1966 as Fred Jackson, owner of the local fish and chip shop. He had completed work on the Summer Wine's 1986 Christmas special and ninth series before his death.
His film credits included appearances in Three Hats for Lisa (1966), Charlie Bubbles (1967), Work Is a Four-Letter Word (1968), The Reckoning (1969), the film version of Nearest and Dearest (1972), Escape from the Dark (1976) and Yanks (1979).
Gladwin served as Northern representative of the Catholic Stage Guild. Despite his lifelong rhotacism (which he concealed when acting by substituting the letter R for a guttural sound), he became well known in British television, especially prominent from 1975 until his death in 1987.
Gladwin died on 11 March 1987, aged 81, in Manchester. He is buried at St Mary's Roman Catholic Cemetery just off the A6 road at Wardley, Greater Manchester.
