Born in Western Australia, Paul DeMasson was trained in ballet from the age of 8, with Kira Bousloff and Kiril Vasilkovsky. At 14, he joined the West Australian Ballet. In 1972, he danced with Roland Petit's Ballet de Marseilles. He performed in Petit's Pink Floyd, La Rose Malade, with Maya Plisetskaya in the title role and toured with the company to Paris. Later, he joined the London Festival Ballet, where he worked with Leonard Massine, Jack Carter, Anthony Tudor, John Taras, Mary Skeaping, Rudolf Nureyev, Barry Moreland and others.

After touring Australia in 1975 with London Festival Ballet's production of Nureyev's The Sleeping Beauty, Paul was invited to join the Australian Ballet as a Senior Soloist by the artistic director, Sir Robert Helpmann in 1976. He was promoted to Principle Dancer in 1980 and danced in all the major classics, as well as many one-act ballets by Glen Tetley, Jiri Kylian, Sir Frederick Ashton, Goh Choo San, George Balanchine and Domy Reiter-Soffer.

In 1988, Paul embarked on a freelance career and performed as actor/dancer in the play, Pastrana, in Melbourne which earned him a no mina tion for best supporting actor in the Melbourne Greenroom Awards. He has also made guest appearances and has been guest teacher with The West Australian Ballet, the Queensland Ballet, Philippines Ballet Theatre, Singapore Dance Theatre, Hong Kong Ballet, Norwegian National Ballet and The National Ballet of Canada. He also worked as Ballet Master and Principle/Character Dancer with Bern Staatsopera, The Australian Ballet and The Royal Danish Ballet. Paul had assisted Jiri Kylian, John Neumeier, Maurice Bejart, Ronald Hynd, Jean-Paul Comelin, Stanton Welch, Stephen Baynes, Boi Sakti as well as co-produced and staged Nureyev’s Don Quixote with Maina Gielgud for The Royal Danish Ballet.

Paul was the Ballet Master with John Nerumeier's Hamburg Ballet before returning to SDT in January 2003.

He has created the concept, narrated, arranged the music and co-choreographed The Little Mermaid with Jeffrey Tan for the recent tribute to Hans Christian Andersen for BUTS.