The cast members broke into song on Virgin Airlines Flight 0970 before they took off on their journey from Brisbane to Sydney.
The DisneyOnBroadway YouTube channel says the Australian cast "felt so elated they decided to sing 'Circle of Life.'" A Brisbane season of the Broadway production had just been announced the same day.
The Lion King musical first debuted in July 1997 at Minneapolis, Minnesota's Orpheum Theatre. The show was an instant success, and premiered on Broadway three months later at the New Amsterdam Theater in New York.
The show is the fourth longest-running Broadway show of all time, and has grossed more than $1 billion in revenue. It is the highest-grossing Broadway production in history.