Lárus started his career with Hamar in Hveragerði and led the Úrvalsdeild karla in assists in 2003[1] and 2004.
He played for KR in 2004–2005 where he averaged 7.2 points and 6.1 assists, he signed with Fjölnir in 2005[4] but returned to Hamar the following season.
He played for SISU BK in Denmark during the 2008–2009 season before returning to Iceland in 2010 and signing with Njarðvík.
[15] On 25 June 2021 he led Þór Þorlákshöfn to its first ever national championship after it beat top-seeded Keflavík 3-1 in the Úrvalsdeild finals.
[17] On 2 October 2021, he led Þór to an 113–100 win against Njarðvík in the Icelandic Super Cup.