Emmanuel "Mannie" Klein (February 4, 1908 – May 31, 1994) was an American jazz trumpeter most associated with swing.

He began recording with The Ambassadors for Vocalion in 1924, went with Paul Whiteman in 1928 and was active throughout the 1930s as a studio musician and playing with Jimmy Dorsey, Tommy Dorsey, Benny Goodman and others. In 1937, he moved to California and worked with Frank Trumbauer's orchestra. In early 194o he appeared on Artie Shaw recordings. He worked on soundtracks and played trumpet for the film From Here to Eternity but was uncredited. He worked with musicians associated with West Coast jazz in the 1950s. Klein voiced-over Ziggy Elman's trumpet parts on the soundtrack of the movie "The Gene Krupa Story".

Klein studied with Max Schlossberg of the New York Philharmonic. Although he did not play first trumpet, he was a member of the NBC Symphony Orchestra under Arturo Toscanini. In 1953, he appeared on the Capitol Records album Concerto In C Minor For Piano by Dmitri Shostakovich and The Four Temperaments by Paul Hindemith with Victor Aller and Felix Slatkin.

During the early 1960s, Mannie Klein appeared on several Dean Martin recordings. He played piccolo trumpet on Hugo Montenegro's hit version of the main theme to the 1966 film The Good, the Bad and the Ugly. In the 1970's Klein toured and recorded as a freelance jazz musician, notably in Holland with the Ted Easton Jazzband and American trombone veteran Spiegle Willcox and tenorist Bert Noah.

Klein died at the age of 86 in Los Angeles on May 31, 1994.