Siyeon is a South Korean actress and singer. She is a former member of SDN48's 3rd generation.
- Stage Name: Siyeon (シヨン)
- Real Name: Jung Si Yeon (정시연)
- Birthdate: March 11, 1983
- Birthplace: South Korea
- Blood Type: O
- Talent Agency: office48
- Abazure (Undergirls B)
- Yaritagariya San (Undergirls G)
- Uekara Natsuko (Undergirls B)
- Owaranai Encore
- She was one of only two members of the group to come from outside Japan (the other was Chen Qu).
- For the 2nd & 3rd Generation performance of Touhikou, she did the spoken parts in her native Korean.