Sophie Helen Rhys-Jones was born on 20 January 1964 the daughter of Christopher Bournes Rhys-Jones and his wife, Mary (née O'Sullivan; 1934–2005). She was the second of their children and first daughter. Sophie has an older brother, David. Sophie was named after her father's sister, Helen, who died in a riding accident more than a decade before Sophie was born. Her godfather is actor Thane Bettany who is her father's stepbrother.
In her early life, her family moved to Brenchley, Kent, where she began to attend school at the Dulwich Preparatory School, before moving on to Kent College, Pembury where she was friends with Sarah Sienesi. She then trained as a secretary at West Kent College, Tonbridge.
Sophie started working in the field of Public Relations for a variety of firms, including four years at Capital Radio. She also worked as a ski representative in Switzerland and spent a year travelling and working in Australia. In 1996, with enough experience behind her,she then launched her public relations agency, RJH Public Relations, which she ran with her business partner, Murray Harkin.
She began dating Prince Edward, the youngest son of Queen Elizabeth, after meeting him at a tennis match in 1993. After a six year courtship, their engagement was announced by Buckingham Palace on 6 January 1999. They were wed on 19 June 1999 at St. George's Chapel at Windsor Castle. Royal guests at the wedding included the Prince's parents, two older brothers, older sister, aunt, three nephews, three nieces, The Sultan of Brunei, Queen Anne-Marie of Greece, The King of Jordan, The Prince of Austrias, Prince Joachim of Denmark and Princess Alexandra of Denmark. Other notable guests included people from the performing arts world in the United Kingdom. It was on this day that Prince Edward was granted the title The Earl of Wessex and Viscount Severn, making his wife The Countess of Wessex and Viscountess Severn. Queen Elizabeth also declared that he would be heir to the Dukedom of Edinburgh after his brother becomes king and his father dies.
In 2001, Sophie was rushed to King Edward VII Hospital after feeling unwell, where it was discovered she was suffering from an ectopic pregnancy. Nearly two years later, she gave birth to her first child, Lady Louise Mountbatten-Windsor on 8 November 2003 after undergoing an emergency C-Section. Her second child, James, Viscount Severn, was born on 17 December 2007 by cesarean section at the same hospital his older sister was born at four years earlier. The children, per prior agreement between the Queen and their parents, will either not use or not have (depending on interpretation) the titles of Prince and Princess, nor the style Royal Highness. However, legally, per Letters patent issued in 1917 (and still remaining in force today) assign a princely status and the style of Royal Highness to all male-line grandchildren of a monarch, therefore, Louise is technically legally HRH Princess Louise of Wessex and James is HRH Prince James of Wessex.