Þórir Guðmundur Þorbjarnarson (born 26 May 1998) is an Icelandic professional basketball player for KR of the Úrvalsdeild karla.

[3] Þórir came up through the junior ranks of KR[4][5] and played his first senior game, at the age of 16, on 7 December 2014, when he scored 31 points against Haukar-b in the Icelandic Basketball Cup.

[3][1][12][13] On 8 January 2020, he tied his career high with Nebraska after scoring 17 points in a 76–70 win against Iowa.

On 12 November he posted 28 points, 15 rebounds and 8 assists in an overtime victory against Stjarnan in the Úrvalsdeild.

[19] On 17 July 2023, Þórir returned to Iceland and signed with reigning national champions Tindastóll.