Rydberg may refer to: People Gerda Rydberg (1858–1928), Swedish artist better known as Gerda Tirén Jan Rydberg, (1923-2015), Swedish chemist who worked on nuclear chemistry and recycling at Chalmers University of Technology Johannes Rydberg (1854–1919), Swedish physicist and deviser of the Rydberg formula Kaisu-Mirjami Rydberg (1905–1959), Finnish journalist and politician Per Axel Rydberg (1860–1931), Swedish-American botanist Sam Rydberg (1885–1956), Swedish composer Viktor Rydberg (1828–1895), Swedish author, poet, and mythographer Viktor Crus Rydberg (1995—), Swedish ice hockey player Physics Rydberg constant, a constant related to atomic spectra Rydberg formula, a formula describing wavelengths Rydberg atom, an excited atomic state Rydberg molecule, an electronically excited chemical substance Rydberg unit of energy (symbol Ry), derived from the Rydberg constant Places Rydberg (crater), a lunar crater named after Johannes Rydberg