Swear It Again是爱尔兰流行乐队西域男孩的首支单曲，一经推出便蝉联英国单曲榜冠军两周，是西域男孩经典曲目之一。

"Swear It Again" is a song by Irish boy band Westlife, released as the first single from their debut album Westlife. It peaked at number one in the UK Singles Chart for two weeks in May 1999. It moved to 182,000 units in the first two weeks of its release and spent 13 weeks on the charts. This made it the first of fourteen UK number-one singles. To date, it is Westlife's only single to have charted in the U.S., peaking at number 20 on the Billboard Hot 100 and ranking number 75 on the Billboard Hot 100 Year End Charts, in 2000. The song was performed live on Miss Teen USA 2000. The single has sold over 365,000 copies to date in the UK and the US and also achieved gold status there.