Kim Seong-yoon

{{Short description|South Korean baseball player (born 1999)}}

{{For|South Korean television director|Kim Seong-yoon (director)}}

{{family name hatnote|Kim||lang=Korean}}

{{Infobox baseball biography

| name = Kim Jeong-yoon

| image =

| image_size =

| team = Samsung Lions

| number = 39

| position = Outfielder

| birth_date = {{Birth date and age|1999|2|2}}

| birth_place = South Korea

| death_date =

| death_place =

| bats = Left

| throws = Left

| debutleague = KBO

| debutdate = June 4

| debutyear = 2017

| debutteam = Samsung Lions

| statyear = June 29, 2025

| statleague = KBO

| stat1label = Batting average

| stat1value = .300

| stat3label = Home runs

| stat3value = 6

| stat4label = Runs batted in

| stat4value = 69

| teams =

• Samsung Lions ({{kboy|2017}}–present)

| highlights =

| update =

| medaltemplates =

}}

{{Infobox Korean name/auto

|hangul = %김성윤

|hanja = 金盛閏

}}

Kim Seong-yoon (also transliterated as Kim Sung-yoon, born February 2, 1999) is a South Korean professional baseball outfielder for the Samsung Lions of the KBO League. At {{height|ft=5|in=4}}, he over-took Kim Sun-bin of Kia Tigers, who stands at {{height|ft=5|in=5}}, to be the shortest player in the KBO when he debuted for the Lions in 2017. He is 4 in (20 cm) shorter than the average players in KBO and tied with Daichi Mizuguchi of Seibu Lions to be the shortest among Major League Baseball (MLB), Nippon Professional Baseball (NPB), and KBO players.{{Cite web|title=Baseball's shortest players stand tall|url=https://koreajoongangdaily.joins.com/2017/06/22/Baseball/Baseballs-shortest-players-stand-tall/3034957.html|website=Korea JoongAng Daily|language=en|access-date=2020-05-08}}{{Cite web|title=Diminutive hitter chasing elusive .400 batting average|url=http://www.koreaherald.com/view.php?ud=20170818000322|date=2017-08-18|website=The Korea Herald|language=en|access-date=2020-05-08}} In 2020, Kim was joined by fellow Samsung Lions second baseman Kim Ji-chan, who also stands at {{height|ft=5|in=4}}.{{Cite web|title=KBO Officially Has its Own Aaron Judge and Jose Altuve|url=https://www.12up.com/posts/kbo-officially-has-its-own-aaron-judge-and-jose-altuve-01e98nzb6dsx|website=12up.com|access-date=2020-05-26}}