Kálmán Széll de Duka et Szentgyörgyvölgy (8 June 1843 – 16 August 1915) was a Hungarian politician who served as Prime Minister of Hungary from 1899 to 1903.

He was born in the ancient Hungarian noble family Széll de Duka et Szentgyörgyvölgy, that originally hailed from Vas County, in the western region of the Kingdom of Hungary.

His father was József Széll (1801–1871), ispán-regent of Vas County, and his mother was a noblewoman, Júlia Bertha de Felsőőr (1817–1873).

Among his Hungarian noble ancestors were his maternal grandfather, Ignác Bertha de Felsőeőr (1780–1847), vice-ispán of Vas County, jurist, landowner, and his maternal great-grandfather, József Sümeghy de Lovász et Szentmargitha (1757–1832), royal counselor, jurist, landowner, and vice-ispán of Zala County.

When Dezső Bánffy's ministry suffered a serious crisis at the end of 1898 and was compelled to resign in February 1899, Széll was entrusted with the formation of a new cabinet.

The obstruction against the provision for defense lasted from the end of January to 4 April 1903, and resulted in the suspension of the constitution ("Ex lex" condition).