Mathias de l'Obel, Mathias de Lobel or Matthaeus Lobelius (1538 – 3 March 1616) was born in Lille, Nord-Pas de Calais, France, and died at Highgate, London, England after serving as a physician to William the Silent and James I of England.
Lobel studied medicine in Leuven and Montpellier. He became physician to William, Prince of Orange, before moving to England and becoming James I's physician and botanist.
He was author of the landmark 1591 publication Icones stirpium, seu, Plantarum tam exoticarum, quam indigenarum :in gratiam rei herbariae studiosorum in duas partes digestae : cum septem linguarum indicibus, ad diuersarum nationum vsum ('Images of plants, both exotic and native, for students of botany, arranged in two parts: with indices in seven languages for the use of different nationalities'), and is credited with the first attempt to classify plants according to their natural affinities, rather than their medical uses.
The plant genus Lobelia and the botanical family Lobeliaceae are named after him. He spent his final years supervising the gardens of Edward la Zouche, 11th Baron Zouche.