| Gunnar Gunnarsson | |
| Fullname: | Gunnar Þór Gunnarsson |
| Birth Date: | 1985 10, df=yes |
| Birth Place: | Iceland |
| Height: | 1.830NaN0 |
| Currentclub: | KR Reykjavík |
| Clubnumber: | 6 |
| Position: | Leftback |
| Years1: | 2003–2006 |
| Years2: | 2006–2007 |
| Years3: | 2007–2010 |
| Years4: | 2011–2020 |
| Clubs1: | Fram |
| Clubs2: | Hammarby IF |
| Clubs3: | IFK Norrköping |
| Clubs4: | KR |
| Caps1: | 54 |
| Caps2: | 45 |
| Caps3: | 55 |
| Caps4: | 131 |
| Goals1: | 0 |
| Goals2: | 0 |
| Goals3: | 1 |
| Goals4: | 2 |
| Nationalyears1: | 2001–2002 |
| Nationalteam1: | Iceland U-17 |
| Nationalcaps1: | 8 |
| Nationalgoals1: | 1 |
| Nationalyears2: | 2003 |
| Nationalteam2: | Iceland U-19 |
| Nationalcaps2: | 5 |
| Nationalgoals2: | 0 |
| Nationalyears3: | 2004–2006 |
| Nationalteam3: | Iceland U-21 |
| Nationalcaps3: | 13 |
| Nationalgoals3: | 0 |
| Nationalyears4: | 2007 |
| Nationalteam4: | Iceland |
| Nationalcaps4: | 3 |
| Nationalgoals4: | 0 |
| Pcupdate: | 28 September 2013 |
| Ntupdate: | 9 September 2007 |
Gunnar Þór Gunnarsson (born 4 October 1985) is an Icelandic football player who last represented KR in Pepsi deildin before retiring after the 2020 season. He left Hammarby IF on 1 November 2007 to sign a three-year contract with IFK Norrköping.
He joined Hammarby IF before the 2006 season, leaving Icelandic club Fram. He is a defender who played most commonly at left back.
His first international appearance for Iceland was against Spain on 28 March 2007.