McIlwain’s national operatic credits include Marcello in Puccini’s La Boheme, Morales in Bizet’s Carmen, Leporello in Mozart’s Don Giovanni, Chief Cameahwait, and Sergeant Floyd in Mager’s Dream of the Pacific. His recent performances include Spencer Coyle in Britten’s Owen Wingrave, Officer Jones in Nembeko’s Sunder, and his debut in Tulsa Opera’s 75th Anniversary production as Haly in Rossini’s L’Italiana in Algeri, where he served as a 2022-2023 Resident Artist.
McIlwain’s concert works include Handel's Messiah, Rossini's Stabat Mater, Saint-Saens' Christmas Oratorio, and Ralph Vaughan Williams' Serenade to Music. Among his musical theatre credits is Joe in Hammerstein and Kern's Show Boat, the Bus/Dryer in Kushner's Caroline or Change, the title role of Sweeney Todd, and Thomas Rutlig in Tazewell Thompson’s groundbreaking Arena Stage production of Jubilee.