Ungmennafélagið Víkingur, also known as Víkingur Ólafsvík, is an Icelandic football club from the town of Ólafsvík located on the west coast of Iceland situated on the western end of the Snæfellsnes. They played in the Úrvalsdeild, the Icelandic top tier, for the first time in 2013.

The team has spent most of its history in the lowest league, but were promoted to the second tier for the 1975 season, but were instantly relegated back to the third tier, then the lowest tier. They didn't participate every season until recently, sending a merged team with other clubs from Snæfellsnes on occasion, and were last part of such a merger in the 2002 season. They sent a team under their name for the 2003 season and were instantly promoted to 2. deild karla, where they played in 2004 and were promoted again. They finished the 2005 1. deild karla season in a respectable fifth and stayed in that division until 2009, when they were relegated. They won the 2. deild in 2010 to bounce straight back up, finishing 4th, their best ever, in 2011. In the 2012 season Víkingur finished 2nd in the league, 9 points ahead of 3rd, to be promoted to the top tier for the first time. They played in the Úrvalsdeild for the first time in 2013. The team got relegated the following season but will play again in the top division in 2016, after having won the 2015 1. deild karla.

Note: Flags indicate national team as defined under FIFA eligibility rules. Players may hold more than one non-FIFA nationality.

For details of current and former players, see Category:Ungmennafélagið Víkingur players.