Lucas was born at Six Nations Reserve, Ontario and was a student of Romain-Octave Pelletier I. He taught at the Toronto College of Music, taught in Utica, New York, and was the musical director at Wesleyan Ladies College in Hamilton, Ontario. In London, he tutored pupils in composition, proofread music for Chappel publishing, and was a correspondent and then editor for the magazine Musical Courier which he later held in New York and Paris. In Sèvres, just outside of Paris, Lucas freelanced as a music transcriber, arranger, lyricist, and translator. He also contributed to Etude, a musical periodical.
Lucas conducted works by George Frideric Handel, Michael Costa, Edvard Grieg, George M. Cohan, and others. He toured the British Isles as a conductor for the Irish musical Peggy Machree, and the United States for Grieg's Peer Gynt.
Lucas' first wife was an English pianist, Clara Asher. His second wife was Gertrude Pidd, a musician. He had a son, British composer and conductor Leighton Lucas (1903 - 1982).
He authored The Story of Musical Form (1908, London).
Lucas composed music for voice, choir, organ, piano and orchestra. He wrote overtures, cantanas, symphonies, operas, chamber music, songs for musicals, lyrics for popular songs and art songs.
His notable works include:
- The Money Spider (opera, circa 1897)
- Overture for Shakespeare's As You Like It, (1899)
- Overture for Shakespeare's Macbeth, (1900)
- Overture for Shakespeare's Othello
- Prelude and Fugue, Opus 38
- The Birth of Christ (cantana, 1901)
- Peggy Machree (musical, 1904)
- The Song of Songs (lyrics,1914)
- The Perfect Song (lyrics)
- Encyclopedia of Music in Canada, Lucas, Clarence
- Free scores by Clarence Lucas at the International Music Score Library Project