The reason Sasha Obama missed her dad's farewell speech would make every parent proud.

There was barely a dry eye in the house as Barack Obama bade farewell to the American public in his final address yesterday.

His 18-year-old daughter Malia was spotted among the Chicago audience, wiping away tears as her father thanked her, her mum, Michelle, and little sister, Sasha, in front of the world.

“For the past 25 years, you have not only been my wife and mother of my children, you have been my best friend,” Obama said, first addressing his wife.

“You made the White House a place that belongs to everybody. And a new generation sets its sights higher because it has you as a role model. So you have made me proud and you have made the country proud.”

There was just one person missing from yesterday's ceremony. Image via Twitter

Then, the outgoing President of the United States turned his attention to his two children, saying: “Malia and Sasha, under the strangest of circumstances, you have become two amazing young women, you are smart and you are beautiful, but more importantly you are kind and you are thoughtful and you are full of passion.

“You bother the burden of years in the spotlight so easily. Of all that I have done in my life, I am most proud to be your dad.”

It was a beautiful tribute to the young women, who've spent the last eight years in the public eye, after inadvertently being thrust into the spotlight.

There was just one problem though: 15-year-old Sasha wasn't there to hear it.

Her absence was quickly picked up by Twitter users and #WheresIsSasha began trending worldwide:

The social media site was flooded with off-the-wall conspiracy theories — not to mention some killer .gifs — but the reason behind the teenager's absenteeism turned out to be nothing short of ordinary.

It was, after all, a school night.

As it happens, Sasha, who attends the elite Sidwell Friends School in Washington DC, was at home. Studying.

The White House confirmed her location to CBS News correspondent Mark Knoller.

He helpfully passed the news on to the fretful Twitterverse.

Fingers crossed she nailed it.