"Oliver's Army" is a song written by Elvis Costello and performed by Costello and the Attractions, from the former's third studio album Armed Forces (1979). The song is a new wave track that was lyrically inspired by the Troubles in Northern Ireland and includes lyrics critical of the socio-economic components of war. Costello had travelled to Northern Ireland and was influenced by sights of British soldiers patrolling Belfast. Musically, the song features a glossy production and a keyboard performance inspired by ABBA, creating a juxtaposition between the lyrics and music that both critics and Costello have pointed out.

Declan Patrick MacManus, known professionally as Elvis Costello, is an English singer, songwriter, record producer, author and television presenter. Per Rolling Stone, Costello "reinvigorated the literate, lyrical traditions of Bob Dylan and Van Morrison with the raw energy and sass that were principal ethics of punk", noting the "construction of his songs, which set densely layered wordplay in an ever-expanding repertoire of styles." His first album, My Aim Is True (1977), is widely regarded as one of the best debuts in popular music history. It spawned no hit singles, but contains some of Costello's best-known songs, including the ballad "Alison". Costello's next two albums, This Year's Model (1978) and Armed Forces (1979), recorded with his backing band the Attractions, helped define the new wave genre. From late 1977 through early 1980, each of the eight singles he released reached the UK Top 30. His biggest hit single, "Oliver's Army" (1979) sold more than 400,000 copies in Britain. He has had more modest commercial success in the US, but has earned much critical praise. From 1977 through the early 2000s, Costello's albums regularly ranked high on the Village Voice Pazz & Jop critics' poll, with This Year's Model and Imperial Bedroom (1982) voted the best album of their respective years. His biggest US hit single, "Veronica" (1989), reached number 19 on the Billboard Hot 100.