"Whatta Man" (also known as "Whatta Man (Good Man)") is a song recorded by South Korean girl group project I.O.I. The song samples the 1968 song "What a Man" by Linda Lyndell. The song was released as a single album by the first sub-unit of the group, with members Nayoung, Chungha, Kyulkyung, Sohye, Yoojung, Doyeon and Somi. It was released as a digital download by YMC Entertainment and distributed by LOEN Entertainment on August 9, 2016 and as a physical single on August 11. The lyrics were written by Nikki Flores, Phillip Bentley, and Seo Jeonga and the music was composed by Emile Ghantous, Steve Daly, Keith Hetrick, Ryan S. Jhun, Michel Schulz, and Fritz Michallik, with additional background vocals from Nikki Flores and Melanie Fontana. Choreography for the song was created by member Chungha. To promote the single album, I.O.I's unit performed the song on several South Korean music programs, including M Countdown and Music Bank. A music video for the title track was also released on August 9.

I.O.I was a South Korean girl group formed by CJ E&M through the 2016 reality show Produce 101 on Mnet. The group was composed of eleven members chosen from a pool of 101 trainees from various entertainment companies: Jeon So-mi, Kim Se-jeong, Choi Yoo-jung, Kim Chung-ha, Kim So-hye, Zhou Jieqiong, Jung Chae-yeon, Kim Do-yeon, Kang Mi-na, Lim Na-young, and Yoo Yeon-jung. They debuted on May 4, 2016, with the EP Chrysalis and actively promoted as a whole and as a sub-unit for less than a year.