lastnames and ethnicity

Korean

1. Kim (Gim)
2. Lee (Yi)
3. Park (Pak, Bak)
4. Choi
5. Cho
6. Cha
7. Cheong (Chung)
8. Jeong (Jung)
9. Nam
10. Ban
11. Seo (Suh)
12. So (Soh)
13. Son (Sohn)
14. Shin
15. Noh (Roh)
16. Baek
17. Bae
18. Oh
19. Ahn
20. Yang

Examples:

Korean: Lee
Chinese: Lee, Li,

Korean: Park
Chinese: Pu, Piao,

Korean: Kim
Chinese: Jin, Kam, Kim

Korean: Moon, Mun
Chinese: Wen, Man, Boon, Bun, Mun

Korean: Chang
Chinese: Zhang, Chang, Cheung, Cheong, Teo

Korean: Yoon
Chinese: Yin, Wan, Oon, In, Een

Korean: Choi
Chinese: Cui, Tsoi, Choi, Chui

Korean: Oh
Chinese: Wu, Woo, Ng, Ngo, La

Korean: Chu, Joo
Chinese: Zhou, Chou, Chau, Chow, Chew, Choo (Jimmy Choo周仰杰)

Korean: Chae
Chinese: Cai, Chai, Choi, Tsoi, Choy…

https://en.wikipedia.org/wiki/List_of_South_Korean_surnames_by_prevalence