In 1993, Wallis earned his MB ChB from the University of Edinburgh, subsequently serving in the Royal Navy for his postgraduate training.

[1] In January 2002, he relocated to Cape Town to complete a qualification as a Fellow of the College of Emergency Medicine, which he earned in 2003.

[1] Wallis is responsible for the provincial EMS system in the Western Cape and for 40 hospital emergency centers.

"[10] Wallis previously served as the President of the International Federation for Emergency Medicine (IFEM), and is currently on the board of directors.

[12] He lives on a farm and in his spare time has set up a guest house, restaurant, and boutique winery,[12] which produced Wellington’s first 5-star wine.