Marguerite Sara Roesgen-Champion (24 January 1894 – 30 June 1976) was a Swiss composer, pianist and harpsichordist[1] who used the pseudonym Jean Delysse.

[2] Roesgen-Champion studied at the Conservatoire de Musique de Genève, notably with Marie Panthès.

As a pianist she performed several piano concertos by Mozart and Haydn.

In 1940 Roesgen-Champion founded a concert series entitled Suites Française which was used a showcase for students of distinction from the Paris Conservatory.

She also supported the Orchestre Jane Evrard (also known as the Orchestre féminin de Paris), founded by Jane Evrard, which was an all-female chamber orchestra that performed contemporary works including the premiere of Guy Ropartz' Petite Suite.