A young woman has captured the moment she asked the man who raised her to officially become her father, in a heartwarming clip that has swept Facebook and landed her thousands of friend requests.

Misty Nicole Knight, from Richton Park, Illinois, shared the three-and-a-half-minute video, which has been viewed 22 million times and shared by more than 18,000 people in just three days.

After asking a family member to film the exchange, she is seen handing Ryan - who is believed to have been married to Misty's mother, Nicole - a box wrapped in brightly-coloured paper with a note stuck to it, asking him to read it aloud.

Misty Nicole Knight posted the video of her surprising her 'dad' Ryan to officially become her father

At first Ryan is reluctant, insisting 'You're going to make me cry,' and begging everyone in the room not to record him.

But Misty - who describes herself on her Facebook page as a Hooters waitress - convinces him to read the letter aloud.

It begins: 'I just want you to know that you are the most amazing man I have ever met.

'You've raised me my whole life, from putting my hair in tight Princess Leia buns, forging my signature in fifth grade, jamming out to alternative music, going on Warped Tour and even our first rock concert together, leading up to us laughing at cats wearing leggings.

Misty pictured with Ryan, who she describes as 'the most amazing' man she has ever met. Ryan, who is believed to have separated from Misty's mother, broke down in tears as Misty asked her to officially adopt her

Ryan is seen reading aloud from the letter, before delving into his box of presents including a Batman onesie

'I know we are so weird together, but that's what makes you you, and I cannot imagine not having you in my life. I'm so grateful to be able to call you Dad.

'You're probably wondering what this letter is for - well, open the damn present already!'

She adds: 'PS. This is bigger than Batman vs. Superman, bigger than how Kylo Ren kills Han Solo - spoiler alert! Alright, I'm impatient - open the box already. It's OK to cry.'

He then unwraps the box to find a Batman vs. Superman onesie and some sweets before Misty tells him: 'Now that's the main surprise.'

The final present is an application for adoption. Ryan, who appears speechless, gives Misty a hug before bursting into tears, as the rest of the family applaud.

In the letter, Misty told Ryan: 'I just want you to know that you are the most amazing man I have ever met'

Emotional scenes: Ryan throws his arms around Misty as he realises she wishes for him to officially adopt her

The heartwarming video has been viewed more than 22 million times since it was posted on Facebook

He says: 'God, I've been wanting to do that forever.'

Posting the video on Facebook on March 6, Misty wrote: 'So everyone has been waiting for this but I finally asked the man that raised me to adopt me. love you with all my heart and can't wait to be a FARREL.'

Hundreds of people took to Facebook to congratulate the pair, with Ashlee Knight writing: 'Omg!! This melted my heart and definitely had tears flowing! Congrats! Love you both!'

Misty's mother Nicole, who is believed to have separated from Ryan some time ago wrote: 'Awww so sweet! I'm so glad you followed through with this! I couldn't have chosen a better father for you! You have a great father! He loves you and your brother so much!!!!!'

Brenda Gewalt commented: 'So happy to finally see it happen!

Misty pictured at her high school graduation in 2014 with Ryan, left, and mum Nicole, right. Ryan can now legally apply to become Misty's 'official' father after she surprised him with a petition for adoption

Misty later took to Facebook to tell friends that her video had been sent into the Ellen show

Another friend said her heart was 'melting', while Crystal Anne Marie said: 'I love this!! My heart is so full!'

It seems that after her video went viral, Misty became an overnight celebrity, taking to Facebook the next day to write: 'Over 2000 shares.. Lol we may be on Ellen. 4 people sent our video in to her already.'