Kelles-Krauz was born in Szczebrzeszyn, Russian Empire and died in Pernitz, Austria-Hungary.

Yale's Timothy Snyder argues that Kelles-Krauz, writing two decades before Hans Kohn and Carlton Hayes, ought to be among the small cluster of turn-of-the-century thinkers regarded as the pioneers of the modern study of nationalism.

He was the son of nobleman and landowner Michał Wilhelm Elehard Kelles-Krauz [pl] and Matylda Daniewska.

He had three younger brothers, Jan Jakub, Bohdan, Stanisław Maciej and sister Matylda.

[1] His youngest brother Stanisław Maciej [pl] was also a PPS activist, senator of the Second Polish Republic (1928-30) and Polish ambassador to Denmark after the Second World War, married to PPS activist Maria Helena Nynkowska [pl].