Born 7 February 1849 at Draumbaer, Vestmannaeyjar, the son of Runolfur Magnusson, born 22 February 1818 in Kross, Rangarvalla, died 20 March 1894; and Ingiridur Bjornsdottir, born in 1817 in Vestmannaeyjar, died 4 July 1870. Bjorn was married to Sigridur Sigvaldadottir in 1878; Sigridur was born 14 August 1851 in Skagafjordur, died 16 January 1939 in Spanish Fork, Utah.
Bjorn joined The Church of Jesus Christ of Latter-day Saints and was baptized 9 May 1874. He was excommunicated for apostasy two years later; however, he and his wife were baptized again 25 March 1883 by Elder Petur Valgardsson. Bjorn remained a faithful member of the Church. Bjorn and his family immigrated to Spanish Fork, Utah in 1887.
Bjorn followed the trade of carpentry and shoemaker; he was often called a jack of all trades, as he could do almost anything that required skill and patience. He died 27 August 1932 and is buried in the Spanish Fork City Cemetery. He was known as Ben Runolfson in Spanish Fork. His death certificate lists him as Bjorn Runolfsen. He is number 317 in Icelanders of Utah.