Tony and Christina Quinn
Pet food
Rank 2017

Quinn, 59, made his pile selling posh pet food to Aussies through VIP Petfoods, which offers gluten-free products and a "Fussy Cat" range. After emigrating in 1980 Aberdonian Quinn and his wife Christina, 58, launched the operation on the Gold Coast, selling most of it in 2015 for A$410m (£250m today). The couple also revived chocolate and liquorice maker Darrell Lea. Last year motoring enthusiast Quinn raced a Lamborghini in the Targa Tasmania rally and spent £2.6m on an Aston Martin Vulcan supercar.