Steeped in the world of theatre almost from birth, as the son of Robert Morley, grandson of Gladys Cooper and godson of Noël Coward, Sheridan Morley served it in many capacities: as a critic, director, notable biographer and broadcaster. Later in his life he devised a number of theatrical entertainments, notably a tribute to Coward, Noël and Gertie, and directed a late Coward play, Song at Twilight.

Sheridan Robert Morley was born in 1941 on the day his father opened in the long-running comedy The Man Who Came to Dinner. He was accordingly named Robert after his father and Sheridan after the character his father was playing, a monstrous creature named Sheridan Whiteside based on Alexander Woolcott, then a celebrated American critic.

Sheridan’s maternal grandmother was the Edwardian beauty and actress Gladys Cooper, and his aunt married the actor Robert Hardy. The intoxicating world of the theatre, to which the major part of his career would be devoted, was around him from the start.

Influential though these and other theatrical contacts would prove to be, the single most important figure in Sheridan’s life was always his father: a larger-than-life figure to emulate, perhaps to envy and impossible to rival. Actor, playwright, wit, and for much of his working life a highly paid West End star, Robert Morley was a hard act to follow, not least because of a marked difference in temperament between father and son. Where Robert invariably radiated an untroubled self-assurance, Sheridan was increasingly to suffer the anxieties of self-doubt.

In many ways his childhood was idyllic. Early years were passed at the family home in Wargrave, Berkshire, until in 1948 Robert’s play Edward, My Son, in which he had starred for 18 months in the West End, transferred to Broadway. Sheridan accompanied his mother and a recently born sister at first to California, staying in Gladys Cooper’s home in Hollywood, then to New York for the best part of a year, followed by an 18-month tour of Australia and New Zealand.

Always an observant child, in Hollywood he was able to witness the dying days of the British colony of movie stars who gathered regularly for cricket matches or for tea on one another’s lawns. Celebrated vistors included Garbo, who came for tea and stayed to do the washing-up.

Returning in 1950 to a foggy and food-rationed England, he was sent to a mildly anarchic school at Sizewell, in Suffolk, where he proved bright enough to pass his O levels in English and French two years ahead of the normal age, a feat that earned him his first mention in the national press. School holidays were spent in Rome, Ravello or wherever else his father was filming, and when teased by fellow pupils about his weight he would change the subject by telling anecdotes of the world-famous figures he had been able to meet, some of whom, after a schoolboy fashion, he had even contrived to interview.

Going up to Merton College, Oxford, in 1960, ostensibly to read modern languages, he spent most of his time cultivating what had become his major interest in life. Merton at this time was prominent in college and university theatre. The actor Oliver Ford Davies and Sam Walters, future artistic director of the Orange Tree at Richmond, were running the college drama society, and one of the senior fellows was Nevill Coghill, subsequently the co-author (with Geoffrey Chaucer) of the hit musical The Canterbury Tales.

Sheridan gradually had to admit that he was not cut out to be an actor but opportunities for direction were there for those determined to seize them, and in his second year he worked as assistant director to Peter Dews on the two parts of King Henry IV at the Playhouse.

Dews was an inspiring and astute director, whose most recent success had been An Age of Kings on BBC Television, where all Shakespeare’s history plays were presented in narrative sequence over eight weeks. Morley would not direct professionally until he was in his fifties but he then said that watching Dews at work had taught him all he needed to know about how to run a company.

It was at Oxford that he met Ruth Leon, who would become his second wife. He met Margaret Gudejko, his Boston-born first wife, in Honolulu while enjoying a restful year teaching in the drama department of the University of Hawaii. They were married in 1965, by which time he had returned to England to become one of the late-night newscasters on ITN, writing and reading the five-minute bulletins that closed the evening transmissions in those days.

Where the BBC had established rigid rules for its news programmes, ITN was innovative and flexible, and he found the congenial atmosphere of the newsroom much to his taste. Even if not a persuasive actor in dramatic roles, he was a natural performer, never at a loss for words, and he continued to be a regular broadcaster for the rest of his professional life.

From reading news bulletins he progressed to appearances in the late-night magazine Date-line, and almost at once found himself covering the lying-in-state of Sir Winston Churchill in Westminster Hall. His instructions were to remain in the studio and voice-over the various eminent personages walking round Sir Winston’s coffin. “There you see Sir Anthony Eden,” he said, “and Prince Charles, and of course old Queen Mary.”

Troubled by a vague memory that old Queen Mary had been dead for some years, he later discovered that the studio manager had inserted stock film of the lying-in-state of King George VI. No viewers complained.

By the time his Dateline contract ended he was already freelancing for The Times, conducting interviews with stage and screen stars as they passed through London and developing the easy conversational style that would later characterise his attractive sequence of Saturday Profiles.

He wrote theatre reviews for trade magazines, then for Tatler and from the mid1970s the International Herald Tribune, but his name was most popularly associated with BBC2’s long-running review magazine Late Night LineUp. It was here that he introduced the New York custom of reviewing shows within moments of the curtain call.

So far his work had been journalistic but one of his first Times interviews, with Noël Coward, was to launch him on a new career as biographer. A Talent to Amuse (1969) appeared when Coward’s reputation had only just begun to emerge from a surprisingly long period of neglect, and this first biography to be written about his life and work — though, at its subject’s request, no mention was made of his sexuality — undoubtedly contributed to his rehabilitation.

Having embarked on the writing of biographies, over the following 30 years Morley produced books on Gertrude Lawrence, Dietrich, Oscar Wilde, both the Hepburns (Katharine and Audrey), David Niven, John Gielgud and a dozen others, including his own father, and finally an autobiography, Asking for Trouble (2002). The biographies are chatty, sometimes inaccurate as well as superficial, and take a generally nostalgic tone.

Always star-struck, he admitted that he would have been happier to have been born a generation earlier, when the stars were brighter.

Yet another career began when he put together excerpts from diaries and letters to convey something of the fondness felt by Coward for his stage partner Gertrude Lawrence. Noël and Gertie, starring Simon Cadell and Joanna Lumley, opened at the King’s Head, Islington, in 1983. Revived a year later, with Patricia Hodge, it ran for nine months at the Comedy, and more than 50 productions have since been mounted around the world. Of all Sheridan’s copious work for and about the theatre this affectionate tribute-show remained closest to his heart.

An anthology of the songs of Vivian Ellis, Spread a Little Happiness, followed, but to celebrate the Coward centenary in 1999 he took the formidable decision to direct one of the plays, Song at Twilight. This was the last in which Coward himself appeared, playing a Nobel-prizewinning writer who happened to be a closet gay. At its first production Coward had intimated that the character was partly based on Somerset Maugham, but of course it was the nearest he came to outing himself. With the involvement of Vanessa and Corin Redgrave and Corin’s wife Kika Markham, the result was a triumphant recovery of a work neglected for a generation.

In 1975 Morley had become theatre critic (and arts editor) on Punch, staying there till this famous weekly reached its sad end. Subsequently he became theatre critic on The Spectator, and in 2004 for The Daily Express.

Morley was a large man who included talking, swimming and eating among his listed interests. Fits of depression troubled his later years, sometimes making work difficult for him. In his autobiography he touches on these but offers no hint as to what might have caused them. Behind the public ebullience there were depths he was not inclined to examine.

Sheridan Morley is survived by his wife, Ruth, and by the son and two daughters of his first marriage, which was dissolved in 1990.

Sheridan Morley, journalist, critic and author, was born on December 5, 1941. He was found dead on February 16, 2007, aged 65