Mirallas moved to Goodison Park from Olympiakos last summer and the forward has been in impressive form in recent weeks after overcoming the hamstring problem that hampered him earlier in the season.
"Everybody knows Mirallas has quality," Fellaini told the Liverpool Echo.
"He can score goals and is an important player for Everton. Every game he can contribute and I think he has. I hope for him that he keeps going like this.
"He can dribble and is involved in the action, which is important for forward players. He can score goals and takes good corners, so he is important for the team. Of course there is more to come from him."
Fellaini and Mirallas are now set to line up alongside each other in Belgium's World Cup qualifying Group A double-header against Macedonia.
"We have a lot of good players now for Belgium," added Fellaini. "I think there are 10 players playing in England. All the time in Belgium the talk is about the Premier League.
"We have a good team and we have two important games which I hope to win. We have some good young players and everybody wants to keep going so we can go to the World Cup."