The Duchess of Cambridge looked to be in an extremely good mood as she was seen laughing and joking with the staff at the performing arts venue yesterday morning.
The visit was of special importance to Middleton, as her great-great-grandfather, Francis Martineau Lupton, was a successful textile manufacturer.
Wearing a $4900 purple Oscar de la Renta peplum style dress, the 37-year-old mum-of-three was taken through the Hamlyn Hall at the Royal Opera House and visited their impressive costume department.
To complete the outfit, Middleton wore black patent heels with a gold buckle and carried an $890 black leather bag by Aspinal of London.
According to The Sun, Kensington Palace said the tour would be part of Middleton "exploring her interest in the use and manufacture of textiles".