New information is provided on the oldest fossil ants (Formicidae), including the description of a new species of †Sphecomyrma (†Sphecomyrminae), a new genus of sphecomyrmines, a new genus of apparent myrmeciines, and a new genus of apparent aneuretines. New material from New Jersey amber (Turonian) includes workers of †Sphecomyrma freyi Wilson and Brown preserved together in the same piece of amber, a worker of an unidentifiable †Sphecomyrma species, and a worker of †Brownimecia clavata Grimaldi, Agosti, and Carpenter (†Brownimeciinae). A new species of †Sphecomyrma in New Jersey amber is described and figured from a worker as †S. mesaki, new species. Two worker specimens in Campanian amber from Canada are described, one of which is described as †Cananeuretus occidentalis, new genus and species, and is tentatively placed in Aneuretinae. From Burmese amber (Albian-Cenomanian) are the oldest, definitive ants, along with ones in amber from Charente-Maritime of France (approximately contemporaneous in age). A new genus and species, allied to †Sphecomyrma, is described from these deposits as †Sphecomyrmodes orientalis, along with a remarkable new “poneroid”, †Myanmyrma gracilis, new genus and species (Myrmeciinae?). A key to the species of †Sphecomyrma is provided, the classification of ants summarized, and the Cretaceous records of Formicidae briefly outlined.