The society was originally founded in 1922 as the Newbury & District Amateur Operatic Society. Like most operatic societies of the time the original repertoire consisted mainly of the classic Gilbert & Sullivan operettas.

After WWII the range of shows broadened to include other operettas, musicals and even an occasional opera. Then, as now, popular Broadway and West End shows only become available for amateur performance when the market for professional productions has been satisfied, but the society was quick to stage big hits as and when they were released, including shows like South Pacific (1961), Oklahoma! (1964) and My Fair Lady (1969). Alongside these the society also staged various concerts and for many years also produced the Newbury pantomime at the Corn Exchange.

As the range of possible material increased, other local groups sprang up alongside "the operatic" to cater for different markets. NOMADS was formed in the 1970s to perform more modern material for a younger audience, and Kennet Opera stages both amateur and semi-professional productions. Time has mellowed the differences between the different groups, who now happily co-exist sharing members, directors, crew, venues, repertoire and even Christmas parties!.

Since 2000, audience numbers and membership interest in operetta has declined, and in 2012 the society decided to change it's name from Newbury Operatic Society to Newbury Musical Theatre Society to more accurately reflect what we now do.