This is a list of foreign players in K League 1.
- Players in bold are currently playing in K League 1.
- Nationality is listed under the official K League player registration; players may acquire multiple citizenship.
- If players have been capped for a national team, this nationality takes precedence over the nationality stated in the official K League player registration database.
- In dual citizen annotation, if dual citizen players have an international career, the country listed in italics is the national team they have played for.
North Macedonia
※ Known as Macedonia before 2019
Serbia
※ Includes players who played during the Federal Republic of Yugoslavia (1992–2003) and Serbia and Montenegro (2003–2006) period
- Nebojša Vučićević (1991–1993 Daewoo Royals)
- Rade Bogdanović (1992–1996 Pohang Atoms)
- Zoran Kuntić (1993 POSCO Atoms)
- Zoran Vukčević (1993 Hyundai Horang-i)
- Goran Jevtić (1993–1995 Hyundai Horang-i)
- Aleksandar Jozević (1993 Daewoo Royals)
- Đorđe Vasić (1994 Ilhwa Chunma)
- Nebojša Maksimović (1994 Ilhwa Chunma)
- Željko Simović (1994 Daewoo Royals)
- Jovan Šarčević (1994–1995 LG Cheetahs)
- Boško Minić (1995 Jeonnam Dragons)
- Saša Drakulić (1995–1998 Busan Daewoo Royals, 1998–2000 Suwon Samsung Bluewings, 2001–2003 Seongnam Ilhwa Chunma)
- Ljubiša Ranković (1995–1996 Ilhwa Chunma / Cheonan Ilhwa Chunma)
- Nenad Nonković (1995–1996 Ilhwa Chunma / Cheonan Ilhwa Chunma)
- Branko Božović (1996 Ulsan Hyundai Horang-i)
- Dražen Podunavac (1996 Busan Daewoo Royals)
- Zoran Đurišić (1996 Ulsan Hyundai Horang-i)
- Radivoje Manić (1996–1997 & 1999–2002 Busan Dawoo Royals / Busan I'Cons, 2004–2005 Incheon United)
- Radmilo Mihajlović (1997 Pohang Steelers)
- Rahim Beširović (1998–1999 Busan Daewoo Royals)
- Zoran Novaković (1998–1999 Busan Daewoo Royals)
- Branko Radovanović (1999 Busan Daewoo Royals)
- Mirko Jovanović (1999–2000 Jeonbuk Hyundai Motors)
- Zoran Milošević (1999–2001 Jeonbuk Hyundai Motors)
- Zoran Urumov (1999–2003 Busan I'Cons, 2003–2004 Suwon Samsung Bluewings)
- Nemanja Dančetović (2000 Ulsan Hyundai Horang-i)
- Zoltan Sabo (2000–2002 Suwon Samsung Bluewings)
- Dragan Stojisavljević (2000–2001 & 2003–2004 Anyang LG Cheetahs / FC Seoul, 2004 Incheon United)
- Dušan Šimić (2003 Busan I'Cons)
- Đorđe Tomić (2004 Incheon United)
- Miodrag Anđelković (2004 Incheon United)
- Dragan Mladenović (2006–2009 Incheon United)
- Ivan Perić (2007 Jeju United)
- Željko Kalajdžić (2007 Incheon United)
- Aleksandar Petrović (2008–2009 Jeonbuk Hyundai Motors, 2009 Jeonnam Dragons)
- Borko Veselinović (2008–2009 Incheon United)
- Lazar Popović (2009 Daegu FC)
- Stevan Račić (2009 Daejeon Citizen)
- Ognjen Koroman (2009–2010 Incheon United)
- Vladimir Jovančić (2012 Seongnam Ilhwa Chunma)
- Zoran Rendulić (2012 Pohang Steelers)
- Miloš Bosančić (2013–2014 Gyeongnam FC)
- Sreten Sretenović (2013–2014 Gyeongnam FC)
- Milan Bubalo (2013 Gyeongnam FC)
- Nikola Komazec (2014 Busan IPark)
- Miloš Stojanović (2014 Gyeongnam FC); also played in K League 2
- Lazar Veselinović (2015–2016 Pohang Steelers)
- Dalibor Veselinović (2017 Incheon United)
- Uroš Đerić (2018–2019 Gangwon FC, 2019 Gyeongnam FC, 2021 Suwon Samsung Bluewings); also played in K League 2
- Bojan Matić (2018 FC Seoul)
- Aleksandar Pešić (2019–2020 FC Seoul)
- Aleksandar Paločević (2019–2020 Pohang Steelers, 2021–present FC Seoul)
- Vladimir Silađi (2021 Gangwon FC)
- Fejsal Mulić (2021–2022 Seongnam FC, 2023 Suwon Samsung Bluewings); also played in K League 2