Lennart Axel Edvard Carleson (born 18 March 1928) is a Swedish mathematician, known as a leader in the field of harmonic analysis.

He did his post-doctoral work at Harvard University where he met and discussed Fourier series and their convergence with Antoni Zygmund and Raphaël Salem who were there in 1950 and 1951.

They include Svante Janson, Kurt Johansson, Warwick Tucker, Bengt Rosén, Per Sjölin, Hans Wallin and Ingemar Wik.

But his proofs were very hard and only understood in the late 80s and early 90s when a general theory of operators arrived and brought mathematicians closer to using his striking ideas with ease.

His proof with Michael Benedicks of the existence of strange attractors in the Hénon map in 1991 led to a new field in dynamical systems.