Energizer Holdings (formerly Eveready Battery), headquartered in St. Louis, Missouri, best known for its pink Energizer Bunny, is an American manufacturer of batteries with a market share of approximately 30%, with markets in over 150 countries. Formerly a division of Ralston Purina (which purchased them from Union Carbide in 1986), the company owns the Energizer and Eveready brands, producing alkaline, carbon zinc , and lithium batteries, as well as button cell batteries for medical equipment, as well as other specialty batteries. The company also manufactures flashlights. In 1999, Energizer sold its rechargeable battery division, although it still markets them for retail sale.

In 2003, Energizer bought razor manufacturer Schick (including the Wilkinson Sword brand) from Pfizer, as part of Pfizer's absorption of Warner-Lambert . This was done in order to even competition with leading razor maker Gillette, which owns Energizer's historic arch-rival Duracell.

Employee Lewis Urry invented the long-lasting alkaline battery, which commands 80% of the consumer battery market, in 1959.