"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.

"What a Man" is a song written by Dave Crawford, and originally recorded for Stax Records' Volt imprint by Linda Lyndell, whose recording reached number 50 on the Billboard R&B chart in 1968. The song was sampled and reinterpreted as "Whatta Man" in 1993 by the trio Salt-N-Pepa with En Vogue, which became a commercial success; reaching the top ten in Australia, New Zealand, the United Kingdom, and the United States. In 2011, German singer Lena Meyer-Landrut covered the song while retaining the original title and lyrics.