"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 1963's 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, Jieqiong, 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. 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.
The single album was a commercial success peaking at number 2 on the Gaon Digital Chart and on the Gaon Album Chart, for its digital (downloads and streaming) and physical sales respectively. It has sold over 64,922 physical copies and 368,469 digital downloads as of September 2016. The single album sold 69,076 physical copies in 2016.