His multifaceted career spans various sectors including farming, industry management, and significant roles in Icelandic politics.

Jón Gunnarsson was born to Gunnar Jónsson, a master electrician, and Erla Dóróthea Magnúsdóttir, a merchant.

In his personal life, Jón married Margrét Halla Ragnarsdóttir, with whom he has three children: Gunnar Bergmann, Arndís Erla, and Arnar Bogi.

His business acumen was further demonstrated in his role as Marketing Manager at Prentsmiðjan Oddi from 1991 to 1993, and later, in co-running the import company Rún ehf with his wife from 1994 to 2004.

As a member of the Althing for the Southwest Constituency since 2007, representing the Independence Party, he has played a pivotal role in shaping various facets of Icelandic governance.