She grew up at 1B Tuengen Allé in the district of Vinderen in Oslo and completed her lower secondary schooling in 1954. She received a diploma in dressmaking and tailoring at the Oslo Vocational School, as well as a diploma from École Professionelle des Jeunes Filles in Lausanne,Switzerland. There, she studied accounting, fashion design, and social science. She also attended the University of Olso, where she earned a degree in French, English and Art History.
She and then-Crown Prince Harlad of Norway began their courtship in 1959. Crown Prince Harald's father objected to the relationship due to her being of non-royal status. Once the young crown prince made it clear with his father that he would marry no one unless he could marry Sonja. Finally, his father argreed as his son was the sole heir to the throne and the whole monarchy was at stake. The two were wed on 28 August 1968. together, they have two children, a grandson, a stepgrandson, and four granddaughters:
- Her Highness Princess Märtha Louise of Norway
- His Royal Highness Crown Prince Haakon of Norway (1973)
- Marius Borg Høiby (stepson, 1997)
- Her Royal Highness Princess Ingrid Alexandra of Norway (2004)
- His Highness Prince Sverre Magnus of Norway (2005)
Upon their marriage, she became Crown Princess Sonja of Norway. She imediately began to perform royal duties both at home and abroad. She established the The Queen Sonja International Music CompetitionThe then-Crown Princess Sonja established this music competition in 1988. It was originally for pianists, but in 1995 the competition became only for singers. The jury consists of diverse authoritative figures in opera and the winners receive a cash amount and prestigious engagements at Norwegian music institutions.
Queen Sonja accompanied King Harald when he swore his oath to uphold the Constitution in the Storting on 21 January 1991. This marked the first time in 69 years that a Norwegian Queen had been present in the Storting. Subsequently, the Queen, frequently together with Crown Prince Haakon, has accompanied the King to the formal opening of the fall session of the Storting and the reading of the Speech from the Throne.
In accordance with their own wishes, King Harald and Queen Sonja were consecrated in Nidaros Cathedral in Trondheim on 23 June 1991. In connection with the consecration ceremony, the King and Queen conducted a 10-day tour of Southern Norway. The following year, the entire Royal Family conducted a 22-day tour of Norway’s four northernmost counties.