This Diamond Ring is a 1965 pop song written by Al Kooper, Bob Brass and Irwin Levine. The hit record, which went to #1 on the Billboard Hot 100 chart, is attributed to Gary Lewis and the Playboys though none of the Playboys played their instruments on the recording and Lewis' vocals were heavily supported by Ron Hicklin's overdubs. The session drummer was Hal Blaine, Carol Kaye played bass and Leon Russell both played keyboards and assisted with production. The song was carried through Snuff Garrett Records.

Stylistically, the song's recording features the then common "basic 'combo' instrumentation...(electric guitar, organ, bass, drums), modal (dorian) inflections in the harmony and melody of the verse and a basic rock beat pattern." Unusually the chorus features timpani and the transition between verse and chorus creates a daring modulation from C minor (dorian) to G-flat major.

"The musical style", writes Brackett, "skims aspects from contemporary rock songs, and is then produced and arranged from the vantage point of 'easy-listening' music." The song's harmonic progression resembles those of Beatles songs such as the G-flat/F/E-flat/D-flat descending bass line ("Bad to Me") and the vi-iii movement ("Please Please me", "I Want to Hold Your Hand", "She Loves You", "And I Love Her" and others). The melodic turn on "true" of "if you find someone whose heart is true" resembles those in "Please Please Me" ("Last night I said these words to my girl") and "Do You Want to Know a Secret" ("nobody knows, just we two").

Al Kooper has reportedly stated many times that he was unhappy with the record and had originally hoped the song would be recorded by a group like The Drifters, although it has been his biggest commercial success as a songwriter. Kooper would later re-visit the song, recording a funky version for his 1976 album "Act Like Nothing's Wrong".