"Once a Day" is a song written by Bill Anderson and recorded as the debut single by American country artist Connie Smith. It was produced by Bob Ferguson for her self-titled debut album. The song was released in August 1964, topping the Billboard country music chart for eight weeks between late 1964 and early 1965. It was the first debut single by a female artist to reach number one on the Billboard Hot Country Songs. This song peaked at number one for the week of November 28, 1964, and it stayed at number one for eight consecutive weeks, a record for a female solo artist for nearly 50 years, until it was surpassed by Taylor Swift's "We Are Never Ever Getting Back Together" in December 2012.

James William Anderson III, known professionally as Bill Anderson, is an American country music singer, songwriter, and television host. His soft-spoken singing voice was given the nickname "Whispering Bill" by music critics and writers. As a songwriter, his compositions have been covered by various music artists since the late 1950s, including Ray Price and George Strait.