Try not to cry watching the sweetest best man speech ever as the brother-of-the-groom, who struggles socially, stands up and thanks his sibling for helping him over the years.

This is the moment that Sam Waldron, 23, announced to a room of people how his brother Jonah Waldron, 27, is his "hero" and "never looked down on me".

Brave Sam talks about how he has autism which can make him scared to interact with people, but his brother reminds him "that being different is a real strength, not a weakness".

He says Jonah's new wife Madison Waldron, 25, has "all the makings of a great sister", and jokes she's married the "second most handsome Waldron".

Remembering his speech, Sam said: "I was really nervous before the speech. Before I stood up, I wasn’t sure if everyone would like my speech, but I got more comfortable as I started reading.

"I felt like I was speaking out to whoever has autism and that I was speaking for the autism community."

Groom Jonah, from Adel, Iowa, USA, said: "Once he began to speak, I couldn’t hold in the tears of happiness."

Brothers Sam and Jonah grew up together and, being only four years apart in age, went to the same school.

Sam said: "My relationship with Jonah is simply amazing, we hang out together and have fun."

Sam was diagnosed with autism when he was seven years old, and didn't find intense social settings easy.

Jonah said: "He would come to see me during the school day, he would come for help with a subject or as a break.

"Myself and my parents were the ones he felt the most comfortable talking to about any struggles that he had socially.

"I also became his Respite Care worker, helping him practice social situations in public settings."

Caring big brother Jonah was even inspired to train as a Special Education Teacher to help other children with special needs.

Jonah and teacher Madison met at Wartburg College, and when Jonah introduced his new girlfriend to younger brother Sam, the two were immediate best friends.

Jonah said: "Once he met Maddy, he felt completely comfortable right away."

The couple got engaged on July 23 while on a trip to Buena Vista, Colorado, and Jonah asked Sam to be his best man as soon as they got home.

"I've always known that I wanted Sam as my best man," said Jonah.

"He was very happy, but also you could see that he was nervous too."

Sam said: "I felt like my dream came true.

"I was nervous at first but then I felt happy because I got to be around my best brother."

Sam spent two whole days perfecting his speech before the big day arrived on July 3 this year.

"I would just sit there in Salida and just read it aloud," he said.

"I read it to my Aunt Colleen, Andrew Hoyt and my Dad many times."

Sam stood up in front of the 170 wedding guests to deliver his speech, where he says he's honoured to be his best man and welcomes Madison to their "nut-filled fudge family".

Jonah said: "My favourite part was when he was explaining to Maddy that she gave him peace, because that is exactly how I would explain the way she is with Sam.

"Everyone I saw was crying and laughing, he mixed all of that together very well.

"It gave me great pride to have him as a brother.

"It is something Maddy and I will always have with us for the rest of our lives."

After he finished, Sam was given a standing ovation and the newly-weds rushed over to tell him how much of a great job he did.

The entire speech was recorded and uploaded to Jonah's TikTok account on July 20, and went viral.

It currently has over 6.2 million views and 760,000 likes, which came as a happy surprise for Sam.

He said: "I felt like I inspired a lot of people so it was good."

The video was filmed on July 3 2021.