The writer passed away on Thursday (23Mar17) at a nursing facility in Mission Viejo, California, his nephew, Ken Maas, told The Hollywood Reporter.
Weiss wrote the stories or screenplays for seven films during his career, six of which starred Presley, beginning in 1961 with Blue Hawaii. His Presley projects also included Girls! Girls! Girls!, Fun in Acapulco, Roustabout, Paradise, Hawaiian Style, and finished with Easy Come, Easy Go in 1967.
He received a joint Writers Guild of America nomination for best movie musical for Roustabout, but lost out to Mary Poppins.
He had one other writing credit with the 1965 movie The Sons of Katie Elder, which starred John Wayne and Dean Martin.
Weiss was also an associate of producer Hal B. Wallis and was present when Wallis screen tested Presley in 1956, and called the moment "one of those life-changing experiences" in 2004 book Elvis Presley: The Man. The Life. The Legend.
Weiss has been buried near his late partner, producer Paul Nathan, at the Hollywood Forever Cemetery in Los Angeles, Maas confirmed.