Lesley McNaught-Mändli (born 10 February 1964) grew up on the family farm in Hinckley, Leicestershire. She began training with Ted Edgar, a successful international show jumper. In 1981 she became a Junior European Champion with her horse One More Time IV, after winning at Aarau, Switzerland.
At the age of 18 she emigrated to Switzerland, where she got a job working for Willi Melliger at his stables near Neuendorf. It was whilst living in Switzerland that Lesley met and married Markus Mandlii, a Swiss show jumper. Riding for Switzerland, Lesley won a silver medal in show jumping at the 2000 Summer Olympics in Sydney.