Mary Anne à Beckett (29 April 1815 – 11 December 1863) was an English composer, primarily known for opera. She was the wife of the writer Gilbert à Beckett, who provided the libretti for two of her operas. Their children included the writers Gilbert Arthur à Beckett and Arthur William à Beckett. Her theatrical connections included her brother, the actor and producer impresario Augustus Glossop Harris, and his eldest son, also an impresario, Sir Augustus Harris.
Mary Anne à Beckett was born in London, the eldest daughter of Joseph Glossop and his wife, Elizabeth, née Feron. Among their other children was the future actor and producer Augustus Glossop Harris, whose elder son was the impresario Sir Augustus Harris. Glossop, a man of doubtful financial means, was at various times lessee of the Royal Coburg Theatre (now called the Old Vic), and manager of La Scala, Milan, and the Teatro San Carlo in Naples. His wife, the daughter of an emigré from the French Revolution, sang professionally under her maiden name, "Madame Feron".
In January 1835 Mary Anne married Gilbert à Beckett, a writer and magistrate. They had two daughters and four sons, including Gilbert Arthur à Beckett and Arthur William à Beckett.
Mary Anne à Beckett composed songs, piano pieces, incidental music, and three operas: Agnes Sorel (1835), Little Red Riding Hood (1842) and The Young Pretender (1846). The most successful of these was the first, described as "an operatic farce", loosely based on the life of Agnès Sorel, mistress of Charles VII of France. The piece, with words by the composer's husband, was the first production at John Braham's St James's Theatre in London in 1835. The anonymous reviewer in The Times dismissed the libretto as "cold, dull and comfortless", but praised some of the music as "evinc[ing] no inconsiderable share of taste and skill". The composer turned down the suggestion that she should conduct the performances herself, declining to make public appearances, but her sister made her debut, very successfully, in this production.Little Red Riding Hood, with libretto by Gilbert à Beckett, opened at the Surrey Theatre in August 1842. A reviewer in The Musical World praised the music, and commented that though it was not conspicuously original it was "adroitly put together, and … is consequently preferable to some loftier doings in loftier places, which, in their aim to be very original, are far less pleasing in their material, and far more clumsily dovetailed."