Los Angeles, California - Barack Obama and Oprah Winfrey have paid tribute to "trailblazing" Hollywood star Sidney Poitier after his death was announced on Friday. He was 94.

The Bahamian-American actor was known for films including In The Heat Of The Night, Blackboard Jungle, and Guess Who's Coming To Dinner - and was the first Black man to win the Oscar for best actor.

Best known for his work during the '50s and '60s, Poitier helped pave the way for generations of Black actors after him.

Former president Obama shared a photo of himself and his wife Michelle standing alongside Poitier after he had awarded the esteemed actor the Presidential Medal of Freedom in 2009.

Britney Spears Paris Hilton declares she and Britney Spears invented selfies: "#IconsOnly"

Obama wrote: "Through his groundbreaking roles and singular talent, Sidney Poitier epitomized dignity and grace, revealing the power of movies to bring us closer together. He also opened doors for a generation of actors."

Famed talk show host Winfrey posted a photo of the pair in a joyful embrace and added an emotional message, saying: "For me, the greatest of the 'Great Trees' has fallen ... My honor to have loved him as a mentor. Friend. Brother. Confidant. Wisdom teacher."

"The utmost, highest regard and praise for his most magnificent, gracious, eloquent life. I treasured him. I adored him. He had an enormous soul I will forever cherish," she added.

More tributes poured in from Hollywood greats throughout the day.

The celebrity memorials continued on the day of Poitier's death.

Reese Witherspoon posted a photo of her and Poitier to Twitter and said: "Today we lost a legend. I was lucky enough to spend some time with Sidney Poitier. As a long time fan, I cherished hearing his incredible stories of how he changed perceptions in Hollywood. "

Singer Diana Ross also paid her condolences to Poitier's family and shared a black and white photo of her and the actor, adding: "A wonderful, great man, will always be remembered."

Rihanna Rihanna stirs up renewed marriage rumors with massive diamond ring!

Mariah Carey, Whoopi Goldberg, Kathy Griffin, George Takei, and Joseph Gordon-Levitt were also among those paying tribute.

Viola Davis described his death as "a big one."

She added on Instagram: "No words can describe how your work radically shifted my life. The dignity, normalcy, strength, excellence and sheer electricity you brought to your roles showed us that we, as Black folks, mattered!!!"

The Prime Minister of the Bahamas, Philip Davis, held a press conference during which he reflected on Poitier's legacy.

He said: "Our whole Bahamas grieves. But even as we mourn, we celebrate the life of a great Bahamian. A cultural icon, an actor and film director, civil and human rights activist and a diplomat. We admire the man not just because of his colossal achievements, but also because of who he was."

Poitier grew up in the Bahamas and returned to America at age 15 and worked in a string of low-paying jobs until he later joined the American Negro Theatre, which had been set up as a community project in Harlem in 1940.

In 1963, he became the first Black winner of the Best Actor trophy at the Academy Awards.

The Academy said on Twitter following his death: "Poitier was barrier-breaking and an enduring inspiration who advanced US racial dialogue through his art. Few movie stars have had or will have the influence Poitier had both on and off screen."