"Are You Lonesome Tonight?" (sometimes stylized as Are You Lonesome To-night?) is a song written by Roy Turk and Lou Handman in 1926. It was recorded several times in 1927—first by Charles Hart, with successful versions by Vaughn De Leath, Henry Burr, and the duet of Jerry Macy and John Ryan. In 1950 the Blue Barron Orchestra version reached the top twenty on the Billboard's Pop Singles chart.

In April 1960, after Elvis Presley's two-year service in the United States Army, he recorded the song at the suggestion of manager Colonel Tom Parker; "Are You Lonesome Tonight?" was Parker's wife, Marie Mott's, favorite song. Its release was delayed by RCA Victor executives, who thought the song did not fit Presley's new (and publicized) style. When "Are You Lonesome Tonight?" was released in November 1960 it was an immediate success in the U.S., topping Billboard's Pop Singles chart and reaching number three on the R&B chart. A month after the song's release, it topped the UK Singles Chart. Presley's version was certified by the Recording Industry Association of America for a Gold Record Award for 1,000,000 copies sold in the United States in 1983. It was upgraded by the RIAA to a 2xPlatinum Record Award for 2,000,000 sales in 1992.

"Are You Lonesome Tonight?" was later recorded by several other artists, with versions by Donny Osmond and Merle Haggard becoming top-twenty hits on the pop and country charts respectively. Billboard ranked "Are You Lonesome Tonight?" number 81 on its "Hot 100 All-Time Top Songs" list in 2008.