Actor who plays the leading male role WordNet 3.0 & Open English WordNet

A leading man is a complimentary term for the actor who is the primary male protagonist in a film, television show, or play, usually the main character who can be an action hero or any sort of man, often including a love interest to the leading lady. Wikipedia

A man who does or can play the lead role in a movie, play or other production; a person who frequently plays such roles. Wiktionary