Douglas began his singing career at the West Australian Academy of Performing Arts (WAAPA), obtaining a Bachelor of Performance. Then followed further study at the Australian National Academy of Music, Victoria, where he trained with Sarah Walker, Gregory Yurisich and Marilyn Richardson. Douglas went on to make his professional debut with the West Australian Opera Company in 1998. What followed was a plethora of scholarships, including the prestigious Elizabethan Theatre Trust scholarship which allowed Douglas to study around the world. He has performed with many opera companies in Australia. Major operatic roles have included Tashtego (Moby Dick) by Jake Heggie, Marcello (La Bohème), Germont (La Traviata), Figaro (The Barber of Seville & The Marriage of Figaro), the Father (Hansel and Gretel), Papageno, Danilo (The Merry Widow), Don Alfonso (Cosi fan tutte), Nardo (La finta giardiniera), Publio (La clemenza di Tito), Capperdocian and 1st Soldier (Salome), Bottom in Britten’s A Midsummer Night’s Dream, and the Father in the modern opera Greek by Mark Anthony Turnage. Douglas has been a principal with Oz Opera and has sung with Opera Australia for several years. Douglas also performed many minor roles in the Australasia tour of The Phantom of the Opera in 2009. He has appeared in concert as a soloist in Orff’s Carmina Burana for the Sydney Philarmonia under Brett Weymark, Brahm's German Requiem for St Stephen's Cathedral, Lieder eines fahrenden Gesellen for Woollahra Philharmonic and other oratorios around Australia such as Handel’s Messiah, the Fauré Requiem, and Haydn and Beethoven masses. He is also a performer in many corporate acts such as The Three Waiters and The Australian Tenors. The last three years he has been a performer in the world tour of The Phantom of the Opera.
Recent performances are Bartolo cover in Il Barbiere di Siviglia for Opera Queensland and Enrico in Lucia di Lammermoor for Opera Van Diemensland and Carmen for Opera Australia and Opera Queensland.