The video, that was originally posted on 29 October by mum Emily Matthews, has been consistently shared over the past month, receiving more than 63 million views.
Commenters are calling it the "cutest baby video of the year". It has been shared one million times.
Matthews, 24, from Tennessee filmed the video which sees three-year-old Waylon squeezing his baby brother Lawless while watching TV.
In the video, she asks Waylon if he loves his brother, to which he nods.
"Can I have him?" she asks.
"No," replies Waylon.
Waylon proceeds to hold his baby brother even tighter and kiss him on the head.
Since the video has gone viral, Matthews said she hopes the video is spreading love over the world.
She told the Jackson Sun: "Honestly, I just hope it has more of an impact on people showing love to each other instead of all the hate. Think about what's really important."
The mum-of-two said Waylon often helps her feed and change Lawless and always dotes on his brother.
She added: "He's the biggest helper I could ever ask for. When Lawless cries, Waylon immediately runs and tells me and if I can't come right away, he will give the baby a dummy and a blanket."
What a cutie.