This dress is causing the greatest debate on social media right now.

The debate began on Tumblr when a user named Swiked posted the image of the dress, along with the message: "Guys please help me — is this dress white and gold, or blue and black? Me and my friends can't agree and we are freaking the f**k out."

While some see it as white and gold, others view it as being black and blue.

The hashtag #TheDress is trending on Twitter and celebrities have also joined the debate about over the colour of this dress.

Meanwhile, Scottish singer Caitlin who has seen the dress in real, came forward to reveal the true colour of the much talked about outfit.

The 21-year-old told Business Insider that her friend's mother had worn it to her friend's wedding.

"I got to the wedding and the mother was wearing the dress," McNeill said. "Obviously it was blue and black."