Jaroslav Kvapil was a Czech poet, theatre director, translator, playwright, and librettist. From 1900 he was a director and Dramaturg at the National Theatre in Prague, where he introduced plays by Anton Chekhov, Henrik Ibsen and Maxim Gorky into the repertory. Later he was a director at the Vinohrady Theatre (1921–1928). He wrote six plays, but is today chiefly remembered as the librettist of Antonín Dvořák's Rusalka.

Kvapil was the principal author of the Manifesto of Czech writers of 1917, signed by over two hundred leading Czechs, favouring the concept of Czech self-government.

He was married to actress Hana Kvapilová from 1894 until her death in 1907.