Atletico head into their Champions League final clash with arch-rivals Real in Lisbon in confident mood after ending their 18-year wait for the La Liga title earlier this month.
Simeone is bidding for his fourth trophy as Atletico manager after winning the league, Copa del Rey and Europa League in just three seasons as the club's head coach.
And Courtois praised the Argentinian's motivational style and attention to detail.
"He's sometimes like an extra player in the group so it's nice to also have a coach that is sometimes close to the players," Courtois told Sky Sports.
"He's a great guy who is always behind the players. In training he is always aware when we train good and that we are not sleeping!"
Courtois, 22, says he is desperate to beat Real for the sake of the fans whose only other European Cup final memory was an unhappy one - a defeat at the hands of Bayern Munich in 1974.
"The supporters could only have dreamed about playing in this final," the stopper said.
"It's been 40 years, so this is not only for the players but for the supporters it is really huge that their team is playing in the final after so many years.
"They (Real) are our rival team so we have to win against them otherwise their fans will talk about it for the whole year. Our supporters really hope we win and naturally we do."
Courtois played a starring role in Atletico's Champions League semi-final victory over his parent club Chelsea.
The Belgian admits it was strange to come up against his employers and revealed he is no closer to discovering where he will be playing his football next season.
"It felt weird because naturally Chelsea bought me in Belgium and they gave me the opportunity to play here," he said.
"Naturally, I wanted to win that game but for the rest of the year I am a supporter of Chelsea. It is not clear at the moment."
On a potential battle with Chelsea number one Petr Cech, Courtois said: "He (Cech) is one of the best goalkeepers in the world. Me and him in the same team is maybe not the healthiest thing.
"The two of us want to play everything so I think nobody will be happy just playing the FA Cup and the League Cup so these are things that we have to talk about and we will see what we arrange."