We have defined "professional" to mean a company where all the singers are paid "more than carfare" for performing. Also, the groups listed produced a fully-staged G&S performance at least once in the past two years and have plans to do G&S again in the next two years. Note that the G&S Archive also has a comprehensive list of performing group websites.

• Carl Rosa Opera Company (London and touring)
• Essgee Entertainment (Mt. Tamborine Queensland AU and touring)
• The Gilbert & Sullivan Opera Company (Buxton, each August)
• Grim's Dyke Opera Company (Harrow Weald, UK)
• Lamplighters Music Theatre
• New York Gilbert & Sullivan Players (New York and touring)
• Ohio Light Opera (Wooster, OH)
• Opera A La Carte (Southern California and touring)
• Opera della Luna (Fringford, Bicester, UK — touring only)
• Swiss Gilbert & Sullivan Company
• Washington Savoyards Ltd. (Wash. DC)

• Atlanta Lyric Theatre (Atlanta, Georgia)
• English National Opera (London)
• Light Opera Works (Chicago)
• Lyric Opera of Chicago (Chicago)
• New York City Opera (New York)
• Opera Australia (Sydney, Melbourne and touring)
• Opera Holland Park (London)
• Opera Omaha (Omaha, Nebraska)
• The Toronto Operetta Theatre (Toronto)
• Welsh National Opera (Cardiff and touring)