| Sigþór Júlíusson | |
| Height: | 1.73 m |
| Birth Date: | 1975 4, df=yes |
| Position: | defender |
| Years1: | 1992–1994 |
| Clubs1: | KA |
| Years2: | 1995–1996 |
| Clubs2: | Valur |
| Years3: | 1997–2004 |
| Clubs3: | KR |
| Years4: | 2005 |
| Clubs4: | Valur |
| Years5: | 2006 |
| Clubs5: | Völsungur |
| Years6: | 2006–2007 |
| Clubs6: | KR |
| Nationalyears1: | 2000 |
| Nationalteam1: | Iceland |
| Nationalcaps1: | 1 |
| Nationalgoals1: | 0 |
Sigþór Júlíusson (born 27 April 1975) is a retired Icelandic football defender.