Fifth Harmony gained fame on the second season of "The X Factor," and although they didn't win (they took third place), L.A. Reid signed the girls to Epic Records.

Fast forward to June 2013, and Fifth Harmony, made up of Dinah-Jane HansenAlly BrookeCamila CabelloNormani Hamilton and Lauren Jauregui, have just released their debut single. 

The song world premiered on syndicated radio show Saturday Night Online Live with Romeo Saturday night, and #MissMovinOnWorldPremiere was the top trending topic worldwide for over two hours. 

Check out the song below and leave your thoughts in the comment section below!

Fifth Harmony called in to Saturday Night Online to chat on the night of the premiere. Check out the interview here:

Check out the video of Fifth Harmony's reaction to hearing their song on the radio for the first time:

Check out their vine video thanking fans: