Peggy Ryan, who died Saturday at a Las Vegas hospital at age 80, was Donald O’Connor’s tap-dance partner in a string of high-spirited, low-budget, music-and-dance features released during World War II. In later years, she played Jack Lord’s secretary in the long-running television series “Hawaii Five-O.”

In their wartime films, Ryan and O’Connor – Universal’s answer to Mickey Rooney and Judy Garland – generally played a pair of young lovers (or siblings) who resort to jitterbugging at each plot turn. Wrote a reviewer in the Chicago Tribune in 1944: “Peggy Ryan and Donald O’Connor must certainly take their vitamins regularly – they have enough energy for six people.”

Ryan became almost completely identified with her role as O’Connor’s co-star.

When she danced with Lou Costello in the campus caper “Here Come the Coeds” (1945), Costello exclaimed, “I feel just like Donald O’Connor!”

Margaret O’Rene Ryan was born August 28, 1924, in Long Beach, Calif., into a vaudevillian family. Her parents were billed as the “Merry Dancing Ryans,” and Peggy was dancing professionally from age 3.

Ryan made her film debut as Jill in “The Wedding of Jack and Jill” (1930), a 10-minute short featuring the “Vitaphone Kids” – a troupe that included the Three Gumm Sisters, Mary Jane, Virginia, and Francis, the latter of whom was later better-known as Judy Garland.

In her teens, Ryan began appearing in feature films, making her debut in “Top of the Town” (1937), in which she shone in a single dance scene. She soon had small parts in a number of films, including an uncredited role in “The Grapes of Wrath” (1940).

Ryan and O’Connor first teamed in “What’s Cookin’?” (1942), which starred the Andrews Sisters playing themselves. Its tagline went, “It’s A Swingeroo… Rootin’, zootin’ swingstars… ‘teen-stars… hot licks and hepcats!” A virtually identical cast appeared in “Give Out Sisters” later the same year.

Other films where Ryan danced with O’Connor include “When Johnny Comes Marching Home” (1942), “Mister Big”(1943),and at least four in 1944, including “The Merry Monahans” and “Bowery to Broadway.”

After 1945, Ryan took time off and worked only occasionally in Hollywood thereafter. Her last film was “All Ashore” (1953), starring, perhaps ironically, Mickey Rooney.

Ryan next moved with her third husband, a show-business columnist and personality, to Hawaii, where she taught dance at the University of Hawaii. She also mounted productions of “Funny Girl” and “The Music Man.”

She made occasional television appearances in the 1940s and 1950s, including on Ed Sullivan’s “Toast of the Town” and Milton Berle’s “Texaco Star Theater.”

After her long-running role as Steve McGarrett’s secretary on “Hawaii Five-O,” she moved to Las Vegas, where she continued to teach tap, produce revues, and occasionally performed.

In 1987, Ryan once again danced with O’Connor, in his stage show “Me and My Shadow.”