A Pretty Girl Milking Her Cow (Cailin Deas Crúite na mBó in the Irish language) is a traditional 18th-century Irish Ballad. The English version is attributed to Thomas Moore (1779–1852). Originally sung in Irish Gaelic, the song was popular through the early 20th century. It enjoyed a revival when an updated swing version sung by Irish-American singer/actress Judy Garland was featured in the 1940 film Little Nellie Kelly. The updated version is true to the original musical air, and incorporated original lyrics by MGM Musical Director Roger Edens, and featured Garland singing the song to George Murphy using some of the original Gaelic lyrics in the first chorus, which was true to the traditional air, before moving into an up-tempo swing version typical of the era.
The song was released as the B-side of the more popular Garland song It's A Great Day for the Irish by Decca Records in 1940. It became a popular song for Irish-Americans during St Patrick's Day celebrations. It remained a popular number for Garland throughout her career, and most notably she sang it live in its original Irish language version in July 1951 at her Theatre Royal concerts in Dublin, Ireland. A Dublin review stated: "Remember the song she sang in "Nellie Kelly" - "The Pretty Girl Milking Her Cow." Judy is providing herself with the Irish version - "Cailin Deas Cruidte na mBo" while in Ireland". Later in 1951, she included the song in her first record-breaking appearance at New York's Palace Theatre, although this time reverting to the new version that combined both English- and Irish-language lyrics. The song is also featured on "Garland at the Grove" on Capital Records, recorded live in 1958 at the Coconut Grove in Hollywood. Singers and groups including Bing Crosby, Ruby Murray, Eileen Barton, Carmel Quinn, Clannad, The Fureys, Blackthorn Ceilidh Band and The Chieftains, among others, have recorded the song in either form or a combination of both. Duck Baker recorded a fingerstyle guitar arrangement.