완득이

유아인

— Do Wan-deuk

Kim Yoon-seok

— Lee Dong-joo

Park Soo-young

— Wan-deuk's Father

Lee Jasmine

— Wan-deuk's Mother

김영재

— Nam Min-gu

Ahn Kil-kang

— Coach

박효주

— Lee Ho-jeong

강별

— Jeong Yun-ha

김동영

— Hyeok-Ju

Jo Deok-jae

— Director of Students

성유빈

— Young Wan-deuk

Kim Sang-ho

— Annoyed Neighbor

Sudip Banerjee

— Hassan

조상건

— Dong-joo's Father

Kim Jong-man

— Waiter

Yoon Kyeong-ho

— Market Man

Kim Yun-tae

— Police