Michael William ffolliott Aldridge (9 September 1920 – 10 January 1994) was an English actor. He was known for playing Seymour Utterthwaite in the BBC Television sitcom Last of the Summer Wine from 1986 to 1990. He also had a long career as a character actor on stage and screen dating back to the 1930s.

The son of Dr Frederick James Aldridge and his wife Kathleen Michaela Marietta White, Aldridge was born in Glastonbury, Somerset, on 9 September 1920. He was educated at Gresham's School, Holt, Norfolk, where he acted in school plays. In his last year at school he played the title role in a production of Othello, a report in The Times noting "M. W. ff. Aldridge (aged 17½ years) was masterly and dignified as Othello and well worthy of the formal designation 'a noble Moor'".

His younger brother John Aldridge became a doctor and medical consultant.

Aldridge started his acting career in August 1939 at the Palace Theatre, Watford, appearing in Terence Rattigan's play French Without Tears. A few days later, World War II broke out. From 1939 to 1940, he was in rep at Bristol, Blackpool, Sunderland, Sheffield, Bradford and Amersham. In 1940, he joined the Royal Air Force and served in Africa, the United States, the Middle East and the Mediterranean, leaving the service in 1945 as a flight lieutenant.

After the war, Aldridge returned to acting, and toured with the Arts Council Midland Theatre Company from 1946 to 1948, but it was not until 1954 that his career started to gain him recognition, when he took a role in Salad Days at the Vaudeville Theatre, where he remained until 1957. He played many roles in musicals throughout his career, usually in supporting roles in which he was highly reliable and professional.

Aldridge's first professional appearance was in the part of Kenneth in French without Tears, at the Palace Theatre, Watford, in August 1939. He was in rep until 1940. His first West End appearance was in This Way to the Tomb, playing the Prologue and the Mechanic, at the Garrick Theatre, 1946; toured with the Arts Council Midland Theatre Company from November 1946 to July 1948; appeared in Nottingham Theatre Trust productions from November 1948 to March 1949, playing Othello in Othello at Nottingham, 1948, and at the Embassy Theatre, 1949; with Birmingham rep, 1949; Old Vic Company at New Theatre, 1949-1950: Love's Labour's Lost, She Stoops to Conquer, The Miser, Hamlet; returned to Arts Council Midland Theatre Company, 1950; Bristol Old Vic, 1951-1952: played Macbeth in Macbeth, Two Gentlemen of Verona, Of Mice and Men; Escapade, at St James's Theatre, Strand, London, 1953–1954; Salad Days, Vaudeville Theatre, 1954; Free as Air, Savoy Theatre, 1957; A Moon for the Misbegotten, Arts Theatre, 1960; Vanity Fair, Queen's Theatre, 1962; The Fighting Cock, Duke of York's Theatre, 1966; at Chichester Festival, 1966–1969, and 1971–1972. Heartbreak House, Lyric Theatre, 1967; The Cocktail Party, Wyndham's Theatre, Haymarket, 1968; The Magistrate, Cambridge, 1969; A Bequest to the Nation, Haymarket, 1970; Reunion in Vienna, Piccadilly, 1972; Absurd Person Singular, Criterion Theatre, 1973; The Tempest, Royal Shakespeare Company at The Other Place, 1974; Jeeves, Her Majesty's Theatre, 1975; Lies, Albery Theatre, 1975; The Bed before Yesterday, Lyric Theatre, 1976; Rosmersholm, Haymarket, 1977;The Old Country, Queen's Theatre, 1978; Bedroom Farce, National Theatre at The Prince of Wales, 1978; The Last of Mrs Cheyney, Cambridge, 1980; Noises Off, Lyric, Hammersmith and Savoy, 1982; The Biko Inquest, Riverside, 1984; Relatively Speaking, Greenwich, 1986.

On television, an early significant role was as criminologist Ian Dimmock in the Granada TV series The Man in Room 17 and its sequel The Fellows (1965–67). His screen work included playing Pistol in Orson Welles' movie Chimes at Midnight in 1967.

In 1974, Aldridge appeared as Grigory Rasputin in the historical drama Fall of Eagles.