Actress Sarah Michelle Gellar took to Instagram yesterday to remember the late Robin Williams, on what was the third anniversary of the comedian and actor's death. Williams passed away on August 11, 2014, with his death ruled as suicide by hanging.

It was also confirmed at the time that the actor had Lewy body dementia - a rare progressive brain disorder. Williams was only 63 years old at the time of his death. He was found at his home in California, and his death has had a profound impact on his family, friends, and fans.

Actress posts warming tribute to comedian and actor, Robin Williams

The 40-year-old actress shared a picture of her and her former co-star on Instagram, fondly remembering Williams and his talents. The picture was accompanied by a touching message, telling Williams that he is always remembered and the "gifts" he has left behind are greatly appreciated.

The actress encouraged everyone to expose themselves to Williams work, telling people to watch movies he was in and experience one of his comedies for themselves. Gellar went on to describe Williams as "a phenomenal actor", referring to him as a "genius" and recalling their friendship.

The star finished the message by informing Williams he is still greatly missed and he is always remembered, particularly at the time of his anniversaries.

The post has received over 120 thousand likes and fans shared their emotions beside the picture, letting others know how the actor's death had impacted them.

Sarah Michelle Gellar and Robin Williams worked together on the TV show "The Crazy Ones" in 2013. Gellar played the role of Williams' daughter, with the show airing for one season.

The "Buffy the Vampire Slayer" star spoke to US Weekly one day after Williams death in 2014, saying the actor had impacted her life greatly and revealing he was like a father to her. She added that he was "an inspiration" and a great person to work for.

Other celebrities take to social media to remember the star

Sarah Michelle Gellar was not the only celebrity who took to social media to remember Robin Williams this year.

Actor Pierce Brosnan posted a picture to his Instagram account on August 3, recalling the filming of "Mrs. Doubtfire", saying he was "so proud" to have known Williams and to have had the opportunity to work with him.

The post received over 42 thousand likes. Fellow actor and comedian Billy Crystal posted on his Twitter yesterday, expressing his sadness at the loss of Williams, saying "words still don't come easily".