In April 2007, Hitchon set a new United Kingdom Under 17 Women"s record with a throw of 49.61m at the Kingston-upon-Hull Air Corps Open meeting. The previous record was 48.94m achieved by Frances Miller of Elgin Harriers at the 2001 IAAF World Youth Championships in Debrecen, Hungary.
In March 2008, at the age of 16, Hitchon set a new junior record with a throw of 59.74m at the United Kingdom Throws event in Birmingham, followed by a 59.49m throw at the Blackpool Open Meeting the same weekend.
In July 2009, Hitchon won bronze in the hammer at the European Junior Championships. In doing so she also improved her own national junior record to 63.18m and took Britain"s first ever European Junior medal in the women"s hammer.
A year later, Hitchon was captain of the United Kingdom women"s team at the IAAF World Junior Championships (Moncton, Canada, 19–25 July), as well as remaining the United Kingdom junior hammer record holder.
In July 2011, Hitchon represented the United Kingdom in the European Under-23 Championships in Ostrava, Czechoslovakian Republic (14–17 July), taking the bronze medal.
At the 2014 Commonwealth Games in Glasgow, Sophie achieved a bronze medal in the women"s Hammer throw with a distance of 68.72m.
This was her first success at a senior level championship.