K-pop Girl Groups

I.O.I Members Profile: Full Names, Ages, Heights, Weights and More

June 28, 2026 | By Kris Lodhi

I.O.I members are Nayoung, Chungha, Sejeong, Chaeyeon, Sohye, Yeonjung, Yoojung, Doyeon, and Jeon Somi.

Origin	Seoul, South Korea
Debut	May 4, 2016
Disbanded	January 29, 2017
Sub Unit	I.O.I Sub-Unit
Number of Members	9
Members	Nayoung Chungha Sejeong Chaeyeon Sohye Yeonjung Yoojung Doyeon Jeon Somi Kyulkyung Mina
Oldest Member	Nayoung
Youngest Member (Maknae)	Jeon Somi
Tallest Member	Doyeon
Shortest Member	Yoojung

I.O.I Former Members Profile

Nayoung

I.O.I member Nayoung

Full Name	Lim Nayoung
Birthday	December 18, 1995
Birthplace	N/A
Age	30 years and 6 months old
Height	5 feet 7 inches (171 cm)
Weight	110 lbs (50 kg)
Zodiac Sign	Sagittarius
Blood Type	O
Education	Dongduk Girls University
Position	Leader, Main Rapper, Lead Dancer, Vocalist
Instagram	@nayoung_lim

Chungha

I.O.I member Chungha

Full Name	Kim Chanmi
Birthday	February 9, 1996
Birthplace	N/A
Age	30 years and 4 months old
Height	5 feet 3 inches (161 cm)
Weight	97 lbs (44 kg)
Zodiac Sign	Aquarius
Blood Type	B
MBTI	ISFJ
Education	Sejong University
Position	Main Dancer, Lead Vocalist, Rapper
Instagram	@chungha_official

Sejeong

I.O.I member Sejeong

Full Name	Kim Sejeong
Birthday	August 28, 1996
Birthplace	Jeonju, South Korea
Age	29 years and 10 months old
Height	5 feet 5 inches (164 cm)
Weight	105 lbs (48 kg)
Zodiac Sign	Virgo
Blood Type	AB
Education	Indeogwon High School
Position	Main Vocalist
Instagram	@clean_0828

Chaeyeon

I.O.I member Chaeyeon

Full Name	Jung Chaeyeon
Birthday	December 1, 1997
Birthplace	Jorye-dong, Suncheon-si, Jeollanam-do, South Korea
Age	28 years and 6 months old
Height	5 feet 5 inches (166 cm)
Weight	108 lbs (49 kg)
Zodiac Sign	Sagittarius
Blood Type	A
MBTI	ISFJ
Education	School of Performing Arts Seoul
Position	Vocalist, Visual
Instagram	@j_chaeyeoni

Sohye

I.O.I member Sohye

Full Name	Kim Sohye
Birthday	July 19, 1999
Birthplace	N/A
Age	26 years and 11 months old
Height	5 feet 5 inches (166 cm)
Weight	105 lbs (48 kg)
Zodiac Sign	Cancer
Blood Type	A
Education	Kyunggi Girls’ High School
Position	Vocalist, Rapper
Instagram	@s_sohye

Yeonjung

I.O.I member Yeonjung

Full Name	Yu Yeonjung
Birthday	August 3, 1999
Birthplace	Seoul, South Korea
Age	26 years and 10 months old
Height	5 feet 6 inches (168 cm)
Weight	92 lbs (42 kg)
Zodiac Sign	Leo
Blood Type	A
MBTI	ESTP
Education	Hanlim Multi Art School
Position	Main Vocalist
Instagram	@uyj__0803

Yoojung

I.O.I member Yoojung

Full Name	Choi Yoojung
Birthday	November 12, 1999
Birthplace	N/A
Age	26 years and 7 months old
Height	5 feet 2 inches (157 cm)
Weight	97 lbs (44 kg)
Zodiac Sign	Scorpio
Blood Type	O
MBTI	ISFJ
Education	Seoul Music High School
Position	Lead Rapper, Lead Dancer, Lead Vocalist
Instagram	@dbeoddl__

Doyeon

I.O.I member Doyeon

Full Name	Kim Doyeon
Birthday	December 4, 1999
Birthplace	Wonju, Gangwondo, South Korea
Age	26 years and 6 months old
Height	5 feet 8 inches (173 cm)
Weight	110 lbs (50 kg)
Zodiac Sign	Sagittarius
Blood Type	O
MBTI	ISTP-A
Position	Vocalist, Visual
Instagram	@lafilledhiver_

Jeon Somi

I.O.I member Jeon Somi

Full Name	Ennik Somi Douma
Birthday	March 9, 2001
Birthplace	N/A
Age	25 years and 3 months old
Height	5 feet 8 inches (172 cm)
Weight	105 lbs (48 kg)
Zodiac Sign	Pisces
Blood Type	O
MBTI	ENFP
Education	Seoyun Middle School, Hanlim Multi Arts High School
Position	Lead Dancer, Lead Vocalist, Rapper, Face of the Group, Center, Maknae
Instagram	@somsomi0309

Kyulkyung

I.O.I former member Kyulkyung

Full Name	Zhou Jieqiong
Birthday	December 16, 1998
Birthplace	Shanghai, China
Age	27 years and 6 months old
Height	5 feet 5 inches (167 cm)
Weight	105 lbs (48 kg)
Zodiac Sign	Sagittarius
Blood Type	O
Education	Shanghai Conservatory of Music; School of Performing Arts Seoul
Position	Lead Dancer, Vocalist, Visual
Instagram	@zhou_jieqiong1216

Mina

I.O.I former member Mina

Full Name	Kang Mina
Birthday	December 4, 1999
Birthplace	N/A
Age	26 years and 6 months old
Height	5 feet 4 inches (162 cm)
Weight	92 lbs (42 kg)
Zodiac Sign	Sagittarius
Blood Type	O
Education	Seoul School of Performing Arts
Position	Lead Dancer, Vocalist, Rapper
Instagram	@_happiness_o

Member Ages: Oldest to Youngest

Member	Birthday	Age
Nayoung	December 18, 1995	30 years, 6 months, 10 days old
Chungha	February 9, 1996	30 years, 4 months, 19 days old
Sejeong	August 28, 1996	29 years, 10 months old
Chaeyeon	December 1, 1997	28 years, 6 months, 27 days old
Kyulkyung	December 16, 1998	27 years, 6 months, 12 days old
Sohye	July 19, 1999	26 years, 11 months, 9 days old
Yeonjung	August 3, 1999	26 years, 10 months, 25 days old
Yoojung	November 12, 1999	26 years, 7 months, 16 days old
Doyeon	December 4, 1999	26 years, 6 months, 24 days old
Mina	December 4, 1999	26 years, 6 months, 24 days old
Jeon Somi	March 9, 2001	25 years, 3 months, 19 days old

FAQs

How many members are in I.O.I?

I.O.I is a 9-member K-pop girl group. The group consists of Nayoung, Chungha, Sejeong, Chaeyeon, Sohye, Yeonjung, Yoojung, Doyeon, Jeon Somi, Kyulkyung, and Mina.

When did I.O.I debut?

I.O.I debuted on May 4, 2016.