AllMusic writer Ashley S. Battel said it is "energetic". Pan-European magazine Music & Media described the song as "upbeat dance pop with a prominent role for Carey's joyous and confident vocals." To mark twenty-five years since the release of Mariah Carey in June 1990, Billboard writer Trevor Anderson wrote a track-by-track review of the album in June 2015. He noted that, being the fourth track on the track listing, it is the album's first up-tempo song and that is "beats new life" into it as a result. However, he felt that some of the rhythmic arrangements and the electric guitar solo during the bridge prevented "Someday" from sounding timeless. Another editor, Larry Flick commented, "One of the front-running pop divas of the '90s picks up the pace with this contagious, new jack-inflected popper that has already proven irresistible at pop radio."
