Lobelia is a genus of flowering plants in the family Campanulaceae comprising 415 species, with a subcosmopolitan distribution primarily in tropical to warm temperate regions of the world, a few species extending into cooler temperate regions. They are known generally as lobelias.

Mathias de l'Obel, Mathias de Lobel or Matthaeus Lobelius was a Flemish physician and plant enthusiast who was born in Lille, Flanders, in what is now Hauts-de-France, France, and died at Highgate, London, England. He studied at the University of Montpellier and practiced medicine in the low countries and England, including positions as personal physicians to two monarchs. A member of the sixteenth-century Flemish School of Botany, he wrote a series of major treatises on plants in both Latin and Dutch. He was the first botanist to appreciate the distinction between monocotyledons and dicotyledons. The Lobelia plant is named after him.