Despite the mistake, La La Land still owned the night by taking home six Oscars including a Best Actress Award that went to Emma Stone.
The surprise win of Best Picture by Moonlight made its Oscar haul for the night to three, after bagging the Screenplay Award and best Supporting Actor prize.
For Best Actor, Cassey Fleck took the award for Manchester by the Sea, while Viola Davis was named best Supporting Actress for Fences.
Damien Chazelle became the youngest filmmaker to win the Best Director Oscar.
The Oscars will be best remembered though for its closing moments when Warren Beatty and Faye Dunaway arrived to announce the best picture winner. Unknown to them, Beatty had been handed the previous winners envelope, and the card read Emma Stone had won best Actress for La La Land. It is from this card that Dunaway read from, mistakenly declaring La La Land to be the best picture and creating what Emma Stone would refer to as "the craziest Oscar moment of all time."
In a statement, PriceWaterHouseCooper apologized for the blunder saying the presenters had been handed the wrong envelope.
"We are currently investigating how this could have happened, and deeply regret that this occurred."