Karl Cook is not the only horse-lover in his family, his mother and his sister are also horse-riders and competitors. Karl began riding at a young age, getting on his first horse around age 8. Karl has been a member of the USA's Young Rider Team. He competed in his first World Cup Final in 2013 in Göteborg and finished at the 11th position. For the last years, Karl Cook has not stopped improving his ride and his results on the World Cup circuit, he won his first World Cup Grand Prix in August, in Langley. 
Karl Cook is also knowed for being Scott Cook's son, who is a co-founder of the software company Intuit, whose current offerings include the tax preparation software TurboTax, the accounting software QuickBooks, and the personal finance website Mint, and for being Kaley Cuoco's boyfriend.