EVP and COO, Wal-Mart U.S.
Wal-Mart Stores
2011 rank: New
Age: 42
Ruiz, who started at Wal-Mart in 1992 as a store management trainee, made the jump from human resources to operations when she took over as COO of the U.S. business in February. Her reach is massive: The U.S. division has 1.4 million associates, more than 3,800 stores, and $264 billion in sales.