Brad Pitt
Actor Brad Pitt poses at the premiere of 'Unbroken' at Dolby theatre in Hollywood, California December 15, 2014.Reuters

International Day of Peace, which is also known as World Peace Day, is celebrated every year on 21 September since 1982, and this year it falls on Monday.

The day is specifically observed for world peace and people across the globe make efforts to free the world from violence and war. It is also dedicated to peace education by the Secretary-General of the United Nations from 2013.

The theme for this year's World Peace Day is "Partnerships for Peace – Dignity for All" and it aims at highlighting the importance of striving for peace by all segments of the society.

Apart from several government and non-governmental organisations, celebrities also play a vital role in driving the world to ceasefire and non-violence.

Last year, around 200 Hollywood celebrities, including Arnold Schwarzenegger, Amy Pascal, Seth Rogen and Josh Charles, raised their voice against Hamas by supporting a statement on a pro-Israel coalition website called "Creative Community for Peace and Friends".

Other popular celebrities who have shared their thoughts on world peace include Brad Pitt, Chris Evans, Charlie Chaplin, Jackie Chan, Ellen DeGeneres and Angelina Jolie. Here are some of their quotes and sayings:

Elayne Boosler: I am thankful the most important key in history was invented. It's not the key to your house, your car, your boat, your safety deposit box, your bike lock or your private community. It's the key to order, sanity, and peace of mind. The key is 'Delete.'

Angelina Jolie: I am a strong believer that without justice, there is no peace. No lasting peace, anyway.

Charlie Chaplin: I am at peace with God. My conflict is with Man.

Jackie Chan: Olympics for me is love, peace, united.

John Denver: Peace is a conscious choice.

Brad Pitt: Perhaps we don't need these religious concoctions to pillow the fear of death. Just the fact that there is an unknown, and something greater, can bring a feeling of peace. That's enough for me.

Morgan Freeman: Martin Luther King Jr. is remembered as our prince of peace, of civil rights. We owe him something major that will keep his memory alive.

Charlize Theron: At the end, the realisation is that she had to get to a place in her life where she could drop her guard and make peace with the fact that whether she had a small amount of time, that she had to kind of live it completely through, instead of living by the rules.

Chris Evans: What if I couldn't handle people's opinions of me? I know that shouldn't dictate a person's degree of peace or happiness in life, but the problem is, I chose a business saturated in judgment.

Ellen DeGeneres: I get those fleeting, beautiful moments of inner peace and stillness - and then the other 23 hours and 45 minutes of the day, I'm a human trying to make it through in this world.

Christopher Lee: My favourite country is Finland because once you get to a certain point, you can drive for hours without seeing a single person. I love peace and quiet - something I don't get very often.

Linda Evans: If there's no inner peace, people can't give it to you. The husband can't give it to you. Your children can't give it to you. You have to give it to you.

Tom Cruise: It's well known I'm a Scientologist, and that has helped me to find that inner peace in my life and it's something that has given me great stability and tools that I use.

Kim Kardashian: My decision to end my marriage was such a risk to lose ratings and lose my fan base. I had to take that risk for my inner peace and to be happy with myself.

Kelly Clarkson: There is no greater feeling than hanging out with my dogs, or just walking around the land with our horses. My rescue ranch is where I feel the most at peace and where I'm reminded of the simple things in life and let the chaos of my crazy work life fade away.