The news was announced on the official Strictly Instagram account today.
The post read: "He's a pop sensation a TV presenter and now a future #Strictly star! Welcome @hrvy to SCD!"
HRVY, real name Harvey Leigh Cantwell, joins the likes of comedian Bill Bailey, EastEnders’ Maisie Smith and popstar Max George in this year’s line-up.
The 21-year-old has had almost 500million views online and previously appeared on BBC’s Friday Download on CBBC.
An aspiring singer, he collaborated with Jonas Blue on their single Younger in 2019 and also supported Little Mix on their 2014 Salute tour.
Fellow YouTube stars Joe Sugg and Saffron Barker have previously appeared on the show.
The news comes as judge Motsi Mabuse has hinted that Bruno Tonioli will not be replaced as he is forced to miss the next series.
The BBC judge is forced to miss the dancing competition this year, which airs on Saturday nights, when it returns in the autumn.
Bruno is having to miss the next season because of other commitments with American show Dancing With The Stars - for which he is also a judge.
However, his co-star and fellow judge Motsi has massively hinted during a chat with Hello! magazine that Bruno will not be replaced when the show returns.
She told the publication: "I think everybody has a special spot on the judging panel and Bruno is not replaceable."
Motsi added: "We all have to adjust. [Remote judging] may be an aspect of the show that we never knew was missing.
"We will have to see what works as we go."
Bruno has said that he is hoping to make the four final episodes.