Jón Bjarnason (born 26 December 1943) is a former member of parliament of the Althing, the Icelandic parliament from 1999 - 2013. An agronomist by training, he served as Minister of Fisheries and Agriculture in the years 2009-2011.
He is a former member of the Left-Green Movement. In 2013 he was a co-founder of Rainbow, a new eurosceptic political party. He did not get reelected in the 2013 parliamentary election.