By Kilian is an eco-luxury perfume brand from Paris, founded by Kilian Hennessy, grandson of the founder of the LVMH group. (The "H" in LVMH stands for Hennessy, the well-known family of brandy makers.)

In 2007, Kilian launched his own perfume house, in line with his family's long tradition of producing luxury goods.

The company emphasizes ecology and sustainability through the use of refillable, reusable packaging. The perfumer's formulas are also available for each fragrance on the official website.

By Kilian has also launched limited editions of several fragrances in the collection, in special luxury packaging. The brand also expanded its range to include evening handbags in 2011.