"leading character" is a correct phrase in written English and can be used in various contexts.
For example: The lead character in the movie was a strong female role model.
Previous hacks allowed players to choose Zelda as the game's leading character and lead her on a quest to save Link.
Cold disgust — unless it leads to comedy — is probably not the most productive attitude to maintain toward your leading character.
And the leading character?
R. J. Palmer: Take the coalition's leading character with artifice?
The city, as ever, is the leading character.
A leading character in this regard is John A. Thain.
Acted in leading character parts, including the title role in the national tour of "Hadrian VII".
Its leading character flits between a Ring Master and an Acrobat, but, ultimately, is left alone.
"Energy in the executive is a leading character in the definition of good government.
Soon they'll be able to put the face of the viewer on to the leading character.
He inhabits the mind of his leading character, but also credits her fastidiousness.
