Welsh National Opera (WNO), opera company based in Cardiff, of international stature in the opera world, touring widely in the United Kingdom and abroad.

Formed in 1943, as an amateur group, the company's first fully staged production was performed in April 1946, a double bill of Cavalleria rusticana and I Pagliacci at the Princess of Wales Theatre, Cardiff. For many years, the company was accompanied by a variety of professional orchestras until, in 1970, a permanent orchestra, the Welsh Philharmonia, was formed. In 1973 the chorus became fully professional, and six years later, the orchestra was renamed the Orchestra of Welsh National Opera.

Since then, the WNO has developed into a significant force in the operatic world. Its productions of Otello by Verdi and the Ring cycle by Wagner in 1986 were particular landmarks, meeting with critical acclaim.

The company remains committed to the principle of bringing opera to as many people as possible, believing opera has a wide popular appeal and should not be élitist. It also encourages young singers by offering them opportunities to sing with the company.

With funding from the Millennium Commission and the Arts Council of Wales Lottery Fund, Welsh National Opera moved to a new home in autumn 2004, the Wales Millennium Centre, part of a £1.5 billion development of Cardiff waterfront.