The Australian Chamber Orchestra (ACO) is an Australian orchestra focused on chamber music based in Sydney.

The Australian Chamber Orchestra was founded by cellist John Painter in 1975.^[1] Richard Tognetti was appointed lead violin in 1989 and subsequently appointed artistic director.^[1]

As well as frequent Australian tours, the Sydney-based Australian Chamber Orchestra often tours Asia, Europe and the US, including regular performances at London's Wigmore Hall, New York's Carnegie Hall and Lincoln Center, Vienna's Musikverein and Washington's Kennedy Center.^[2]

In 2014 an album of the orchestra, featuring the American soprano Dawn Upshaw as soloist, won three Grammy Awards.^[3] The orchestra appears in the films Musical Renegades^[4] and Musica Surfica^[5] and the television series Classical Destinations series two.^[6]

In 2005, ACO Collective, a second ensemble combining emerging artists and Australian Chamber Orchestra musicians was formed as a training and regional touring orchestra.^[7]

The ACO musicians perform on a collection of 11 Golden Age string instruments, including three Stradivarius violins.^[8] Richard Tognetti performs on a 1743 Guarneri del Gesù violin,^[9] on loan from an anonymous benefactor. Principal Violin Satu Vanska performs on the 1726 Belgiorno Stradivarius on loan from Guido and Michelle Belgiorno-Nettis,^[10] Principal Cello Timo-Veikko Valve performs on a 1616 Brothers Amati Cello on loan from the ACO Instrument Fund^[11] and Principal Violin Helena Rathbone plays a 1732 Stradivarius violin on loan from an anonymous benefactor.^[12]

In 2021, the Orchestra was described as Extremely Online.^[13]