Kilian Hennessy (French pronunciation: ​[kiljɑ̃ ɛnɛsi]; 19 February 1907 – 1 October 2010) was a French business magnate of Irish extraction, and co-patriarch, with Maurice his first cousin, of the Hennessy cognac company. Hennessy’s grandson, who shared his name, founded a niche perfume line called By Kilian; in 2016, the younger Hennessy sold the line to Estée Lauder rather than LVMH.