He is married to Marit Arntsen (born 11 December 1952) whom he married in 1972. He has the two sons Ole Robert Reitan (born October 5, 1971) and Magnus Reitan (Born March 11, 1973). He resides in his houses in Spain and in Lade Gård, Trondheim.
Reitan played keyboard in the music group Four Jets in the 1960s.
Son of Jewish parents from Hungary and the Netherlands, Reitan established his first shop in Trondheim in 1972, in cooperation with his Father. In 1979 he established the grocery chain store REMA 1000, which came to be a great success. By 1990 every village in Norway with more than 10,000 inhabitants had a Rema 1000 shop. During the 1990s the chain expanded in Denmark, Sweden, Poland, Hungary and Slovakia.
He and his 2012 book was the subject of an editorial in Klassekampen. The editorial highlighted his idea of him governing Norway without being elected by popular vote. His idea is that he could be appointed by Norway's king. The editorial described these ideas as "undemocratic dirt".