Carl Gustaf Mosander (Kalmar 10 September 1797 – Lovö, Stockholm County 15 October Swedish chemist. He discovered the elements lanthanum, erbium and terbium.

Mosander went to school in Kalmar until he moved to Stockholm with his mother at age 12. There he became an apprentice at the Ugglan pharmacy. He took his pharmacy examination in 1817, but had an interest in medicine and matriculated as a student in the Karolinska Institute in 1820 and graduated with his Master of Surgery degree in 1824. He worked teaching chemistry at the Institute and as an assistant in the mineralogical collection of the National Museum of Natural History. Jöns Jacob Berzelius was his teacher of chemistry during his medical studies, and in 1836 he succeeded him as professor of chemistry and pharmacy in the Karolinska Institute.