Judith McKenna

McKenna oversees a stunning $121 billion in revenue as head of Walmart’s international division. She’s shown no qualms about making equally big moves, such as her plan to invest $1.2 billion in the company’s China supply chain. In April, McKenna hit a setback when regulators blocked the merger of Walmart’s U.K. operation, Asda, with Sainsbury’s; she’s pivoted and is now considering an IPO for the business.