"Birthday" is a song by American R&B singer K. Michelle, for her fourth studio album "Kimberly: The People I Used to Know" (2017).

[2] Speaking on the track Michelle stated in an interview with Billboard magazine "Birthday is just the fun song going out, but I can honestly say this is my best vocal album and you will get those in ballads like "Brain On Love" and "No Not You".

However, K has some tricks up her sleeve; intensifying her vocal delivery as the song progresses, moving from a cooed approach to a more rhythmic, but still half-sung second verse.

"[4] Vibe praised the song stating "The song, which is the second single from the forthcoming Kimberly: The People I Used to Know, is perfect for both the club scene and the bedroom, as K. provides smooth, sultry vocals that later transition into a rap that brings major vibes.

"[3] Rap-Up stated "On the seductive “Birthday,” the Memphis songstress caters to her man.