The OAO performs almost exclusively in the Opera House Orchestra pit of the Joan Sutherland Theatre.
OAO's core strength is 53 players (compared with Sydney Symphony's 110) but is currently down to 42 (November 2020), due to Opera Australia making 16 positions redundant during the global pandemic.
More than 120 other musicians may join the OAO as casual musicians during a financial year; this is due in part to Occupational Health and Safety Act NSW 2000 requirements regarding noise levels associated with working in the Sydney Opera House orchestra pit.
Composers Puccini, Verdi, Handel, Bizet and Wagner are standard parts of the repertory.
In 1992 the orchestra was hired to record Antony Partos' music for Alison Maclean‘s drama film Crush, orchestrated by Derek Williams and conducted by Dobbs Franks.