The striker, who scored twice in Saturday's 6-2 win over Dundee United in the Scottish Premier League, had been expected to leave Parkhead in the summer following a number of disciplinary problems.
"It's up to Anthony," Lennon told Sky Sports News. "If he keeps playing like that it's not a difficult decision.
"I have always liked him and he's an important player."
Stokes has scored three goals in eight appearances for Celtic this season.