
I.O.I [Ideal of Idol] (아이오아이)
- Debut (Y-M-D): 16-05-04
- Disbanded: 17-01-29
- Label: YMC Entertainment
- Music Videos:
- Korean MVs: Dream Girls, Whatta Man, Very Very Very
- Albums:
- Korean: Crush [Pre Release Single], Chrysalis, Whatta Man [Single], Hand in Hand [Single], Miss Me?, Downpour [Single]
- Fan Name: N/A
- Logo:

Members:

- Stage Name (Hangul): Nayoung (나영)
- Position: Leader, Rap
- Final Rank: 10th
- Real Name: Lim Nayoung (임나영)
- Birthday (Y-M-D): 95-12-18
- Nationality: Korean
- Height: N/A
- Blood Type: A
- Label: PLEDIS Entertainment
- Formerly in: Pristin


- Stage Name (Hangul): Chungha (청하)
- Position: Dance, Vocal
- Final Rank: 4th
- Real Name: Kim Chungha (김청하)
- Birthday (Y-M-D): 96-02-09
- Nationality: Korean
- Height: 161cm
- Blood Type: B
- Label: MHN Entertainment
- Now in: Solo

- Stage Name (Hangul): Chaeyeon (채연)
- Position: Vocal
- Final Rank: 7th
- Real Name: Jung Chaeyeon (정채연)
- Birthday (Y-M-D): 97-12-01
- Nationality: Korean
- Height: 164cm
- Blood Type: A
- Label: MBK Entertainment
- Now in: DIA

- Stage Name (Hangul): Kyulkyung (결경)
- Position: Dance, Vocal
- Final Rank: 6th
- Real Name: Zhou Jieqiong (周潔瓊)
- Birthday (Y-M-D): 98-12-16
- Nationality: Chinese
- Height: 166cm
- Blood Type: O
- Label: PLEDIS Entertainment
- Formerly in: Pristin
- Now in: Solo

- Stage Name (Hangul): Sohye (소혜)
- Position: Dance, Vocal
- Final Rank: 5th
- Real Name: Kim Sohye (김소혜)
- Birthday (Y-M-D): 99-07-19
- Nationality: Korean
- Height: 163cm
- Blood Type: A
- Label: S&P Entertainment

- Stage Name (Hangul): Yeonjung (연정)
- Positon: Main Vocalist
- Final Rank: 11th
- Real Name: Yoo Yeonjung (유연정)
- Birthday (Y-M-D): 99-08-03
- Nationality: Korean
- Height: N/A
- Blood Type: N/A
- Label: Starship Entertainment & Yuehua Entertainment
- Now in: WJSN


- Stage Name (Hangul): Mina (미나)
- Position: Dance, Rap, Vocal
- Final Rank: 9th
- Real Name: Kang Mina (강미나)
- Birthday (Y-M-D): 99-12-04
- Nationality: Korean
- Height: 162cm
- Blood Type: O
- Label: Jellyfish Entertainment
- Formerly in: Gugudan


- Stage Name (Hangul): Somi (소미)
- Position: Center, Vocal, Maknae
- Final Rank: 1st
- Real Name: Ennik Somi Douma/Jeon Somi (전소미)
- Birthday (Y-M-D): 01-03-09
- Nationality: Korean-Canadian
- Height: 172cm
- Blood Type: O
- Label: THEBLACKLABEL
- Now in: Solo