Thirteen Strings is a chamber orchestra in Ottawa, Ontario, Canada.
It was founded in 1976 by Brian Law, then conductor of the Ottawa Symphony Orchestra, who led the ensemble until 1991.
Its initial members were drawn from the National Arts Centre Orchestra.
After Law left in 1991, various guest conductors directed the ensemble, including Calvin Sieb.
In 2012 the Thirteen Strings' members were Martine Dubé, Andréa Armijo Fortrin and Manuela Milani as violin I; Brigitte Amyot, Maria Nenoiu, David Thies-Thompson and Solange Tremblay as violin II; Guylaine Lamaire and Peter Webster on viola; Julian Armour and Thaddeus Morden on cello; and Hilda Cowie on bass, with additional non-string members Louis-Pierre Bergeron (horn), Marie Bouchard (harpsichord), Julie Paul (oboe), and Camille Churchfield and Christian Paquette (flute).