Koenig died at his home in North Hollywood in Los Angeles, his agent Zachery McGinnis said in a statement, citing the cause of “old age” without further details.
The actor was known for playing the youthful Russian navigator Chekov in the original television series, as well as in several “Star Trek” feature films.
“Today we mourn the passing of Walter Koenig, whose talent, warmth, and unforgettable performances left a lasting mark on generations of fans around the world,” read the statement.
“Thank you, Walter, for the memories, the inspiration, and for boldly going where few have gone before.”
The actor died surrounded by his daughter and niece, added the statement.
Ensign Pavel Chekov first appeared in the iconic series at the start of its second season, in 1967.
The character was meant to appeal to younger viewers.
William Shatner, who played (Captain James T Kirk) and Leonard Nimoy (Mr. Spock) were both in their mid-thirties at the onset of the series, nearly over the hill by the era’s standards.
Koenig was 30 when he was cast, and producers hoped he’d appeal to teens, with his mop-top hairstyle not unlike Davy Jones of the Monkees, the famed TV-produced pop band.
Born in Chicago and raised in Manhattan, Koenig was the child of Lithuanian immigrants.
He earned a bachelor’s degree in psychology and initially planned a career as a psychiatrist.
But acting proved a good bet.
“Star Trek” was given a tepid reception when it debuted, but it eventually snowballed into a cultural phenomenon, spawning a universe of spinoff series along with the films, and a rabid fan following.
The original show ran from 1966 to 1969.
Koenig told The Los Angeles Times that when it was canceled he was “totally at sea” with “no reason to get up in the morning.”
But the series soon found massive cult fame, with “Trekkie” super fans who have kept it alive to this day.
Koenig signed on to a film franchise that followed, becoming a mainstay of “Star Trek” movies released between 1979 and 1994.
He also appeared in non-canon spin-offs, and was in the space drama TV series “Babylon 5.”
Throughout his career he also posted a number of writing credits, and also worked on computer games.
Koenig married Judy Levitt, who also appeared in “Star Trek” films, in 1965.
She died in 2022.
“My heart is heavy,” wrote George Takei, Koenig’s “Star Trek” co-star who played Sulu in the franchise.
“Walter was more than Chekov. He was a writer, a teacher, a thoughtful man, and a loyal friend. To the fans who loved him for so many years, thank you. He loved you too,” Takei wrote on Facebook.
“Rest well, my dear friend. Keep navigating a steady course.” (AFP)