Samuel M. Rubin, who was known as ''Sam the Popcorn Man'' for making popcorn almost as popular in New York City movie theaters as jokes and kisses, died on Thursday. He was 85.

He died in Boynton Beach, Fla., his daughter, Karen Rubin, said.

Movies had prospered without popcorn until the Great Depression, when theater owners scrambled to make up for reduced ticket prices by turning to ''audible edibles.'' The appetite of moviegoers was so great that from 1934 to 1940, the nation's annual popcorn harvest grew from 5 million to 100 million pounds.

Marty Winter, who worked for Mr. Rubin and in turn employed him over their careers of more than 60 years in the movie concession business, recalled that Mr. Rubin saw popcorn being made in Oklahoma City on a visit around 1930 and started selling it at concessions he controlled when he returned to New York.

But Mr. Rubin's daughter and another longtime business colleague, Carl Levine, said it was not until the early 1950's that Mr. Rubin began to sell popcorn in a major way. At the time, his company, ABC Consolidated, now part of the Ogden Corporation, had the refreshments concession for major movie chains in the New York metropolitan area, including RKO, Brandt and Loews.