| Şemsettin Baş | |
| League: | Turkish Basketball League |
| Height Ft: | 6 |
| Height In: | 5.75 |
| Weight Lbs: | 210 |
| Position: | Shooting guard / small forward |
| Birth Date: | 4 January 1973 |
| Birth Place: | Istanbul, Turkey |
| Nationality: | Turkish |
| Career Number: | 7 |
| Career Start: | 1990 |
| Career End: | 2010 |
| Years1: | 1990–1991 |
| Team1: | Tekelspor |
| Years2: | 1991–1992 |
| Team2: | Paşabahçe |
| Years3: | 1992–2000 |
| Team3: | Tofaş |
| Years4: | 2000–2001 |
| Team4: | Pınar Karşıyaka |
| Years5: | 2001 |
| Team5: | Avtodor Saratov |
| Years6: | 2001–2002 |
| Team6: | Galatasaray |
| Years7: | 2002–2005 |
| Team7: | Türk Telekom |
| Years8: | 2005–2006 |
| Team8: | Galatasaray Cafe Crown |
| Years9: | 2008–2009 |
| Team9: | Potalı Spor |
| Years10: | 2009–2010 |
| Team10: | TED İstanbul |
| Cyears1: | 2014–2018 |
| Cteam1: | Bursaspor |
| Cyears2: | 2019–2020 |
| Cteam2: | CSO Voluntari |
Şemsettin Baş (born January 4, 1973, in Istanbul, Turkey) is a retired Turkish professional basketball player and lastly was head coach of CSO Voluntari. At 6 ft 5.75 in (1.97 m), he played as a shooting guard and small forward.
He is of Bosniak origin and cousin of former NBA and Euroleague player Mirsad Türkcan.