LOS ANGELES — David Cassidy, a heartthrob singer and actor whose poster adorned the walls of tens of thousands of bedrooms of teen girls in the 1970s, died Tuesday at a hospital near his home in Fort Lauderdale, Fla. He was 67.
He had been hospitalized with liver and kidney failure.
Mr. Cassidy portrayed the shaggy-haired guitarist Keith Partridge on the sitcom ‘‘The Partridge Family.’’ At the height of his popularity, he commanded a rabid fan base that drew comparisons to those of Elvis Presley and the Beatles, with The New York Times reporting that after the 21-year-old’s gallbladder was removed in 1971, fans called for the gallstones to be covered in bronze and sold alongside clippings of his hair.
Mr. Cassidy’s entrails remained off the market, but for several years his likeness was emblazoned on posters, push-out cards, coloring books and lunchboxes, as the band he led on television — the Partridge Family, a group that featured his stepmother Shirley Jones — became one of the decade’s defining pop acts, beloved by a mostly female audience and derided by critics who heard only bubble-gum blandness.
Jones, an Oscar-winning dramatic actress from ‘‘Elmer Gantry’’ (1960) who was better known for her wholesome star turns in such movie musicals as ‘‘Oklahoma!’’ (1955) , played a widow who performs with her five children, traveling aboard a psychedelic bus from venues that ranged from a feminist rally to a prison.
Mr. Cassidy was the group’s lead singer and guitarist. A skinny 20-year-old who still looked like a teenager, he said he had little in common with the staid, occasionally doltish youngster he played. The son of divorced show business parents — his father was Tony-winning actor Jack Cassidy — he nurtured a love of rock music.
The quintet scored its first chart-topper with ‘‘I Think I Love You’’ (1970), a breezy pop song written by Tony Romeo for the program’s eighth episode.
Featured on the first of eight albums by the Partridge Family, the song was recorded with Mr. Cassidy, Jones, and a group of studio musicians who replaced their younger counterparts on the show. It was followed by hits including ‘‘Doesn’t Somebody Want to Be Wanted’’ and “I’ll Meet You Halfway.’’
Mr. Cassidy embarked on a solo career beginning with the 1971 record ‘‘Cherish’’ and began performing to sold-out stadiums.
‘‘Attendance at a David Cassidy concert is an exercise in incredulity,’’ Life magazine reported in 1971. ‘‘Hordes of girls, average age 11 and a half, with hearts seemingly placed inside their vocal cords, shout themselves into a frenzy. ... After, being unable to rip off a piece of David’s clothing or a hunk of his hair or a limb of his body, they rush out to buy David Cassidy records or posters.’’
Mr. Cassidy later described himself as ‘‘emotionally stunted’’ and ‘‘paranoid’’ during this period, overwhelmed by the attention of his fans and the simultaneous demands of touring and acting. ‘‘I feel burnt up inside,’’ he said in 1974, announcing his retirement.
Mr. Cassidy veered from television to theater to music, eventually finding solace in breeding horses and slowly coming to terms with what he described as his unbreakable connection with Keith Partridge — ‘‘a shallow airhead,’’ as he described the character, who was ‘‘supposed to be funny. . . . I didn’t ever think that people would assume I was that guy. But they did.’’
Mr. Cassidy was born in New Jersey and moved to California as a teenager. He struggled in school but began taking parts in plays and on television, eventually leading to his big break on “The Partridge Family.”
Mr. Cassidy worked on several other series. A 1978 appearance on “Police Story” earned him an Emmy Award nomination. He also performed the title role in the Broadway production of ‘‘Joseph and the Amazing Technicolor Dreamcoat’’ in the 1980s.
In later years, Mr. Cassidy wrote books about the toll stardom had taken on him and about his own struggles with substance abuse. He revealed this year that he had dementia.
After watching his mother, Evelyn Ward, struggle with dementia, he had worked with groups to educate others about Alzheimer’s disease.
Mr. Cassidy was married and divorced three times. In addition to his stepmother, he leaves a son, Beau, a singer and former Boston University student; a daughter, Katie, an actress; and three half brothers: Patrick, Ryan, and Shaun.