| Darko Kostić | |
| Position: | Head coach |
| Height M: | 1.85 |
| Birth Date: | 30 September 1978 |
| Birth Place: | Smederevo, SR Serbia, SFR Yugoslavia |
| Nationality: | Serbian / Greek |
| Draft Year: | 2000 |
| Career Start: | 1997 |
| Career End: | 2015 |
| Career Position: | Point guard |
| Career Number: | 5, 10, 6 |
| Coach Start: | 2015 |
| Years1: | 1997–1998 |
| Team1: | Filippos |
| Years2: | 1998–1999 |
| Team2: | Okapi Aalstar |
| Years3: | 1999–2000 |
| Team3: | Ratiopharm Ulm |
| Years4: | 2000–2001 |
| Team4: | Okapi Aalstar |
| Years5: | 2001–2002 |
| Team5: | Smederevo 1953 |
| Years6: | 2002–2003 |
| Team6: | Radnički Belgrade |
| Years7: | 2003–2004 |
| Team7: | Chemosvit |
| Years8: | 2004–2005 |
| Team8: | BKM Lučenec |
| Team9: | Salesianos |
| Years10: | 2006–2009 |
| Team10: | Ermis Lagkada |
| Years11: | 2009–2012 |
| Team11: | Doxa Lefkadas |
| Years13: | 2012–2015 |
| Team13: | Livadeia |
| Cyears1: | 2015–2016 |
| Cteam1: | OKK Beograd (assistant) |
| Cyears2: | 2016–2018 |
| Cteam2: | OKK Beograd |
| Cyears3: | 2018 |
| Cteam3: | Academic Bultex 99 |
| Cyears4: | 2019–2020 |
| Cteam4: | Vršac |
| Cyears5: | 2020–2022 |
| Cteam5: | Novi Pazar |
| Cyears6: | 2022 |
| Cteam6: | Kolubara LA 2003 |
Darko Kostić (Serbian: Дарко Костић, Greek, Modern (1453-);: Ντάρκο Ράλλη (Ntarko Rallis); born 30 September 1978) is a Serbian–Greek professional basketball coach and former player.
Rallis had two stints with the Belgian team Okapi Aalstar where played during 1998–99 and 2000–01 season.[1] In between he played for the German team Ratiopharm Ulm.[1] [2] In 2003, he moved to Slovakia where he played for two seasons for Chemosvit Svit and MBK Lučenec.[3] Also, he played for the Ecuadorian team Salesianos Club Guayaquil.[4]
On 2 November 2011 Rallis signed for Doxa Lefkadas of the Greek A2 League.[5] He also played for the Greek A2 League teams Ermis Lagkada, and Livadeia.
Prior to the 2016–17 season Kostić was named as a head coach of OKK Beograd after one year he spent there as an assistant coach of the head coach Vlade Đurović.[6] He left the club in June 2018.
On 30 July 2018 Kostić became a head coach for Bulgarian team Academic Bultex 99.[7] On 27 December 2018 Academic parted ways with him following the loss against Beroe.[8]
On 4 January 2019, Kostić was named as a head coach of Vršac of the Basketball League of Serbia.[9] In February 2020, he left Vršac.
On 16 June 2020, Kostić became a head coach for Novi Pazar.[10] [11]