Montalban died Wednesday morning at his Los Angeles home of complications related to old age, said his son-in-law, Gilbert Smith.
Within the entertainment industry, Montalban was widely respected for his efforts to create opportunities for Latinos, although he and others believed that his activism hurt his career. In 1970, he founded the nonprofit Nosotros Foundation to improve the image and increase employment of Latinos in Hollywood.
"He paved the way for being outspoken about the images and roles that Latinos were playing in movies," said Luis Reyes, co-author of "Hispanics in Hollywood" (2000).
On Wednesday, actor Edward James Olmos called Montalban "one of the true giants of arts and culture."
"He was a stellar artist and a consummate person and performer with a tremendous understanding of culture . . . and the ability to express it in his work," Olmos told The Times.
Montalban was already a star of Mexican movies in the 1940s when MGM cast him as a bullfighter opposite Esther Williams in "Fiesta" and put him under contract. He would go on to appear alongside such movie greats as Clark Gable and Lana Turner.
When major film roles dried up for him in the 1970s, he turned to stage and eventually TV, where he was familiar to millions as the mysterious host whose signature line, “Welcome to Fantasy Island,” opened the hit ABC show that aired from 1978 to 1984.
While "Fantasy Island" was renewing Montalban's career and giving him financial stability, he also won an Emmy for his performance as Chief Satangkai in the 1978 ABC miniseries "How the West Was Won."
In the 1970s and '80s, Montalban was also familiar to TV viewers as a commercial spokesman for Chrysler. He was later widely spoofed for his silky allusion to the “soft Corinthian leather” of the Chrysler Cordoba, although no such leather existed.
While making "Fantasy Island," Montalban also gave one of his best movie performances -- as Khan Noonien Singh in the “Star Trek II: The Wrath of Khan” (1982), a follow-up to a beloved 1967 “Star Trek” television episode that also featured Montalban.
New Yorker magazine critic Pauline Kael said Montalban's performance as Khan "was the only validation he has ever had of his power to command the big screen."
Born Nov. 25, 1920, in Mexico City, Montalban was the youngest of four children of Castilian Spaniards who had immigrated in 1906 to the city, where Montalban's father owned a dry goods store.
Montalban came to Los Angeles as a teenager with his oldest brother, Carlos, who had lived in the city and worked for the studios.
"I felt as if I knew California already, because of the movies," Montalban said in "Reflections: A Life in Two Worlds," the 1980 autobiography he wrote with Bob Thomas.
Montalban studied English at Fairfax High School, where an MGM talent scout noticed him in a student play. He was offered a screen test, but his brother advised him against taking it and took him on a business trip to New York City.
The handsome Montalban soon found himself the star of a short film that was made to play on a screen atop a jukebox. That three-minute movie, which debuted at the Hurricane Bar in midtown Manhattan, led to small roles in plays.
When his mother's illness took him back to Mexico, Montalban got a one-line role in a parody of "The Three Musketeers," starring Cantinflas. Around that time, he also met Georgiana Belzer, a model and Loretta Young's sister, whom he married in 1944. She died in 2007.
Montalban intended to stay in Mexico, where his film career was taking off, but MGM wanted him for "Fiesta." In the 1947 musical, he had a memorable dance scene with a young Cyd Charisse.