Charles O'Flynn (1897–1964) was an American songwriter known for his contributions during the Tin Pan Alley era, a period of popular music in the United States. His career spanned from 1921 to 1947, during which he crafted lyrics for numerous songs. One of his most notable works is the song "Smile, Darn Ya, Smile," which gained renewed popularity after being featured in the film "Who Framed Roger Rabbit." O'Flynn collaborated with various composers and lyricists, contributing to a range of songs that were performed by popular orchestras and artists of the time. His work includes collaborations with renowned musicians such as Al Sherman, Al Hoffman, and Ernesto Lecuona, among others. Some of his other notable songs include "Dr. Jazz's Raz-Ma-Taz," "When You Waltz With The One You Love," and "Swinging in a Hammock." His legacy is preserved in the recordings and performances that continue to celebrate the vibrant era of Tin Pan Alley music.