Gaspar Cassadó i Moreu (5 October 1897 – 24 December 1966) was a Spanish cellist and composer of the early 20th century. He was born in Barcelona to a church musician father, Joaquim Cassadó, and began taking cello lessons at age seven. When he was nine, he played in a recital where Pablo Casals was in the audience; Casals immediately offered to teach him. The city of Barcelona awarded him a scholarship so that he could study with Casals in Paris.
He was also the author of several notable musical hoaxes, notably the "Toccata" that he attributed to Girolamo Frescobaldi.
The personal papers of Cassadó's father are preserved in the Biblioteca de Catalunya. Gaspar's own papers, along with those of his wife, the pianist Chieko Hara, are preserved at the Tamagawa University Museum of Education.
On the invitation of his great friend Alicia de Larrocha, with whom he had a cello-piano duo (touring extensively with him from 1956-58), Gaspar Cassado played concerts and led frequent classes at Academia Marshall in Barcelona. The Professor of Cello chair at Academia Marshall is named after Gaspar Cassado and held since 2018 by Professor Jacob Shaw.