Hepburn's last role, a cameo appearance, was as an angel in Steven Spielberg's Always, filmed in 1988. This film was only moderately successful.
"Our mother often spoke about her love of chocolate and how it lifted her spirit, so we're sure she would have been proud of her role as the face of Galaxy. The advert perfectly captures her playful spirit and we hope audiences enjoy it as much as they enjoyed her movies," said Hepburn's sons, Sean Ferrer and Luca Dotti.
The commercial - which will air for the first time Sunday during a break from Mr. Selfridge on ITV, sees Audrey sitting on a crowded bus wondering when she can enjoy her hidden bar of Galaxy.
The campaign also sees the return of Galaxy's famous tagline Why have cotton when you can have silk.