Anna Buck Nickels (born Ohio, June 10, 1832; died Corpus Christi, Texas, January 3, 1917) was an American cactus collector and florist. She was for many years one of the most important collectors, cultivators, and popularizers of the cactus of Mexico and southern Texas. The standard author abbreviation A.B.Nickels is used to indicate this person as the author when citing a botanical name.