"Who Can It Be Now?" is a song by Australian band Men at Work. It was the second single and first track from their 1981 debut album, Business as Usual. "Who Can It Be Now?" was first released as a single in Australia in June 1981, prior to the recording of the rest of the album. The track peaked at #2 on the Australian singles chart in August that year and went on to reach #1 in the USA and #45 in the UK in 1982. As one of Men at Work's biggest hits, it was featured on their later compilation albums, and a live version can be found on Brazil.

The lyrics of "Who Can It Be Now?" feature the narrative of a reclusive, perhaps paranoid man who hears knocking at his house door and wishes to be left in solitude. The presence of a "childhood friend" is mentioned, and the bridge lyrics give the impression that the narrator fears once again being taken away to a mental institution. Musically, the song features prominent saxophone lines and a mid tempo beat. Its chorus vocals, which make up the song title, feature a melody that is echoed through saxophone in a call and response fashion. The second chorus pushes the anxious lyrics further and becomes flush with vocal harmony.

"Who Can It Be Now?" remains a popular symbol of New Wave music and has been featured on numerous 1980s compilations. The song appears on the game Karaoke Revolution Partyand can be heard in "I Don't Wanna Know Why the Caged Bird Sings," an episode of The Simpsons. David Fricke of Rolling Stonecommended it by noting "Ham's blowsy sax and the rousing chorus of voices raised in alcoholic harmony spark the rugged boogie of 'Who Can It Be Now?'" Allmusic's Stephen Thomas Erlewine called the song an "excellent single that merged straight-ahead pop/rock hooks with a quirky New Wave production and an offbeat sense of humor." Heather Phares reviewed the song specifically and summed up by saying "In keeping with current trends but just quirky enough to be instantly memorable, the song seems custom-built for repeated play; it's easy to see why it became one of 1982's biggest hits, as well as a definitive New Wave single."