McCallum's career as producer began with Pennies from Heaven (1981), the film version of the 1978 BBC TV drama, for director Herbert Ross and writer Dennis Potter.

During the 1980s, McCallum also produced movies with filmmakers including David Hare (Strapless); Neil Simon (I Ought to Be in Pictures); Harvey Fierstein, whose HBO film Tidy Endings received two CableACE Awards;[3] and Nicolas Roeg's Castaway.

[4][5] Several years after their first meeting, Lucas was preparing his first weekly live-action television program, The Young Indiana Jones Chronicles, and turned to McCallum to produce the ambitious series, which was to be shot in 35 countries.

With a unique perspective on the eventful early life of Indiana Jones – including its cinematic qualities, an emphasis on storytelling and characters, and an enticing promise of new adventures each week – McCallum helped attract a stellar list of writers and actors to the creative ranks of the series.

Among the directors with whom McCallum worked on the series were Bille August, Nicolas Roeg, David Hare, Mike Newell, Deepa Mehta, Terry Jones, Gavin Millar, Simon Wincer, and Carl Schultz.

To further test the nascent digital technology just then becoming available, in part from developments they made on Young Indiana Jones, McCallum produced revised versions of A New Hope, The Empire Strikes Back, and Return of the Jedi – released in 1997 as the Special Editions.