| Steinar Dagur Adolfsson | |
| Birth Date: | 25 January 1970 |
| Position: | defender |
| Youthclubs1: | Vikingur |
| Years1: | 1988 - 1994 |
| Clubs1: | Valur |
| Years2: | 1995 |
| Clubs2: | KR Reykjavik |
| Years3: | 1996 - 1998 |
| Clubs3: | IA Akranes |
| Years4: | 1999 - 2001 |
| Clubs4: | Kongsvinger[1] |
| Clubs5: | UMF Skallagrimur |
| Caps4: | 34 |
| Goals4: | 2 |
| Nationalteam1: | Iceland U16 |
| Nationalcaps1: | 7 |
| Nationalgoals1: | 0 |
| Nationalteam2: | Iceland U17 |
| Nationalcaps2: | 2 |
| Nationalgoals2: | 0 |
| Nationalteam3: | Iceland U18 |
| Nationalcaps3: | 13 |
| Nationalgoals3: | 3 |
| Nationalteam4: | Iceland U21 |
| Nationalcaps4: | 17 |
| Nationalgoals4: | 0 |
| Nationalyears5: | 1991–1999 |
| Nationalteam5: | Iceland |
| Nationalcaps5: | 14 |
| Nationalgoals5: | 1 |
Steinar Dagur Adolfsson (born 25 January 1970) is a retired Icelandic football defender.
In his early career he played for Valur, KR Reykjavik and ÍA Akranes. He joined Kongsvinger IL in 1999, and played semi-regularly the first two seasons. He left after the 2001 season.[1]
He was extensively capped for Iceland on youth level, especially U18 and U21,[2] and was subsequently capped 14 times and scored 1 goal for Iceland.