Arranged for String Quartet, When Irish Eyes Are Smiling" is a lighthearted song in tribute to Ireland. Its lyrics were written by Chauncey Olcott and George Graff, Jr., set to music composed by Ernest Ball, for Olcott's production of The Isle O' Dreams, and Olcott sang the song in the show. It was first published in 1912, at a time when songs in tribute to a romanticised Ireland were very numerous and popular both in Britain and the United States. During the First World War the famous tenor John McCormack recorded the song.

The song continued to be a familiar standard for generations. Decades later it was used as the opening song on the radio show Duffy's Tavern. The song has been recorded on over 200 singles and albums and by many famous singers, including Bing Crosby, Connie Francis, and Roger Whittaker.

The song gained notoriety in Canada after the so-called Shamrock Summit between Canadian Prime Minister Brian Mulroney and U.S. President Ronald Reagan held on Saint Patrick's Day, 1985. At the end of the evening, the two leaders and their wives jointly sang "When Irish Eyes Are Smiling," intended to celebrate both leaders' Irish heritage. Mulroney was extensively criticized in the Canadian press for a "cloying performance" said to symbolize his government's excessive closeness to Reagan's.