Hollywood's reigning royalty -- the focus of new biographies; Sir Larry: The Life of Laurence Olivier, by Thomas Kiernan. New York: Times Books. 302 pp. $16.95. Cary Grant, The Light Touch, by Lionel Godfrey. New York: St. Martin's Press. 256 pp. $10.95. Richard Burton, by Paul Ferris. New York: Coward, McCann & Geoghegan Inc. 328 pp. $13.95. Elizabeth Taylor: The Last Star, by Kitty Kelley. New York: Simon & Schuster. 448 pp. $14.95. Elvis, by Albert Goldman. New York: McGraw-Hill Book Company. 598 pp. $14.95. Fonda: My Life As Told to Howard Teichmann. New York: New American Library. 372pp. $15.95. Bette: The Life of Bette Davis, by Charles Higham. New York: Macmillan Publishing Company. 316 pp. $13.95.

It never rains, it pours; so goes the old saw. In recent months, publishers have unleashed a deluge of entertainers' biographies. The hapless reader who sets sail through this storm of paper and ink is doused by more details than one person can absorb. Memory abandons ship after a futile attempt to keep straight the complexities of movie chronologies, musical careers, and multiple marriages.

But generalities float into reach, and one climbs aboard them to dry out - to wring from the soaking some picture that is larger than the sum total of details.

The broadest and most attractive generality is the idea of the popular performer as royalty. Cary Grant's biographer, Lionel Godfrey, goes so far as to call movie stars the ''true royalty of the twentieth century.''

Albert Goldman, a journalist, successfully pursues this idea to an extreme in his brutal expose of Elvis Presley. He notes that Americans, in particular, seemingly need ''to set up kings and worship them.'' He says these ''kings'' include elected officials (didn't people believe in John F. Kennedy's ''Camelot''?) as well as rock idols, movie stars, and other popular celebrities.

Unlike ''Elvis,'' which wallows in regal allusions, or ''Elizabeth Taylor, The Last Star,'' which - like Goldman's book - lavishes detail on its subject's royal hauteur and spoiled excesses, the other books listed above don't rely heavily on the idea of the star as potentate, but almost all allude to it.

For example, Paul Ferris contrasts Richard Burton's sooty, hardscrabble childhood as the son of a Welsh coal miner to his kingly demeanor as he approached adulthood. Ferris describes him as cutting a commanding figure when costumed for the part of a prince, king, or conqueror.

Howard Teichmann, on the other hand, implies that image of the star as royalty by going to great pains to portray Henry Fonda as the hardworking common man who loves to garden and changes his baby son's diapers aboard an airplane. Fonda, he says, ''never thinks of himself as a star.'' Here we have the head of one of Hollywood's crown families who looks more like the man-next-door than a monarch.

Similarly, Charles Higham, remembering a long-ago interview with Bette Davis, appreciatively notes that, ''unlike most stars, Bette Davis doesn't lurk at the top of a regal staircase, to descend only when the guest has been kept waiting long enough.''

Finally, curiosity about our royalty - whether or not we take them seriously - reasonably explains why sales of all these books are expected to go well.

Generalizations aside, the books vary considerably in depth and polish. Here are seven short profiles.

Sir Larry.

There is ''something in a name,'' Sir Ralph Richardson says in the opening chapter of this eloquent but flawed biography. ''Had Larry grown up to be Laurence Oliver, he'd never have grown up to be the actor he was. An actor , perhaps, but hardly one with his dash and sweep. 'Oliver' sort of stumbles off the tongue, whereas 'Olivier' flows and soars.''

Kiernan captures the ''dash and sweep'' of the renowned Shakespearean actor's troubled, tempestuous life. Olivier charmed American movie audiences 43 years ago with his portrayal of the hot-blooded stablehand, Heathcliff, in ''Wuthering Heights.'' It was one of his few successes on screen.

In real life, Olivier was equally passionate, says Kiernan, who recounts the actor's extramarital affair with actress Vivien Leigh (Scarlett O'Hara in David O. Selznick's ''Gone With the Wind''), whose mental illness led their subsequent marriage to tragedy.

Kiernan's liberal use of quotations from Olivier's friends and colleagues enlivens his book. But many are left anonymous, which is an irritation to the reader.

Even more irritating, since this is one of the best books of the lot, is the way the author's writing stumbles toward the end. Most awkward, for example, is Kiernan's failure to comment on Olivier's reaction to Leigh's early death.

Cary Grant.

It is appropriate that Lionel Godfrey dedicates his book to all the endearing characters Grant immortalized on film, because the actor, who appeared so natural on film, breathed life into even the flimsiest role. It would be delightful to encounter in real life a man as debonair, witty, and kind as C. K. Dexter Haven -- the reformed ne'er-do-well Grant portrayed in ''The Philadelphia Story.''

Although he attempted straight drama many times, Grant's bailiwick was light comedy. Ironically, he achieved the comedic fame for which his countryman, Olivier, at first yearned.

A congenial man on and off the screen, Grant throughout his career eluded reporters' questions by fending them off with clever, empty conversation. Furthermore, Godfrey indicates that the actor's friends and ex-wives have loyally maintained his privacy.

The reader, however, may be left with the feeling that Godfrey could have been more persistent in digging for sources who could round out his sketchy picture of Grant's life.

Nevertheless, his light, humorous style is pleasurable, and he touches on some unexpected territory, such as Grant's experimental use of hallucinogenic drugs two decades ago.

Richard Burton.

In the early 1950s, London's theater world considered Burton heir to Olivier's Shakespearean crown. But Burton spurned the British stage for most of his career in favor of making lucrative but mostly mediocre American movies and sheltering his income abroad.

The opening chapters of this book offer a charming description of Burton's boyhood village and the schoolmaster-mentor who adopted him and launched his career.

Ferris doesn't dig deeply into husband-wife relationships. But he does carefully examine Burton's professional achievements and the way the actor's second wife, Elizabeth Taylor, affected his career.

Ferris also deftly unwinds the skeins of half-truths Burton wraps around stories about his youth.

Elizabeth Taylor.

No yarns Burton could spin about Taylor could live up to the eccentricity of the life Kitty Kelley recounts so cunningly.

Although Kelley's book abounds in ugly details (for example, Taylor's appalling household slovenliness, which contrasts sharply with her personal fastidiousness) and perversely funny anecdotes, it is not derisive. Kelley, it seems to me, likes her subject.

Directors either loved or loathed Taylor, who could toil like a trooper and turn in an outstanding performance (''Who's Afraid of Virginia Woolf?'') or could wreak havoc on a film set (''Cleopatra''). The havoc during the latter movie arose, in part, because of health problems precipitated in some instances by excessive drinking and taking drugs, the author charges.

Ferris and Kelley, in their respective books, clearly indicate that it was Burton who first pursued Taylor, but it was the actress who set the marriage trap. Burton reportedly would have been content with a spicy affair.

Elvis.

Biographer Goldman focuses on numerous bizarre and distasteful oddities about the late, reclusive rock idol, such as absorption by a weird blend of Christian and occult readings that led him to believe he had supernatural powers. And to top off his pile of dirty laundry, Goldman recounts Elvis's successful attempt to obtain official status from President Nixon as a special agent of the Bureau of Narcotics and Dangerous Drugs, to help in his antidrug campaign with teen-agers.

Although he sneers too often at Elvis's backward, hillbilly childhood and his fattening culinary tastes, Goldman is not completely without respect or compassion for his subject. In particular, he praises the singer's early creativity and bemoans the musician Presley might have become had he not crossed paths with the greedy, Svengali-like Tom Parker, who transformed him into a schlock movie star and gaudy Las Vegas sideshow attraction.

Fonda.

It is a downright relief to read this book after wading through the Goyaesque lives of Elvis and Taylor.

Teichmann's warm and respectful orchestration of Fonda's memories - as well as those of his children, friends, two former wives, and Shirlee, the Midwesterner to whom the Nebraska-born actor has been married for 13 years.

Although Fonda towers in this book, he does not come up smelling as sweet as the pines he enjoys planting. The stage and screen actor was a deeply flawed man whose family quailed at his ''repressed . . . terrifying'' anger and longed for the words of love he found so difficult, until recently, to speak.

Bette Davis.

Despite a provocative prologue about Davis's middle-age career decline and the lively opening chapters about her spirited but difficult New England childhood, Charles Higham's book dissolves into an uninspired chronicle of the actress's prodigious movie career, ailments, and family troubles.

Davis in her prime played commoners and queens, infusing all her roles with the toughness that was her trademark. Like Olivier, she caught her love of theater from a doting mother.

Higham suggests that from her divorced father, Davis gained the feeling of being unwanted, which drove her to ''make an overwhelming mark on the world.''