The actor, 46, starred as Gaz in cult Noughties sitcom Two Pints Of Lager And A Packet Of Crisps, also landing roles in dramas Line Of Duty and Broadchurch.
He joined the cast of ITV soap Coronation Street in 2021 as “out-and-out baddie” drugs lord Harvey, and also starred in Hollyoaks in the early part of his career.
Mellor’s other credits include police comedy drama No Offence, and Casualty.
The announcement was made on BBC Breakfast ahead of the 20th series, which will see audiences returning to the studio this year, with the launch show scheduled to be recorded on September 7.
Mellor said: “I’m honestly so chuffed to be taking part in Strictly Come Dancing this year.
“Not going to lie, it’s totally out of my comfort zone and I know it will be a huge challenge but that’s what life is all about.
“This is also my mum’s favourite show and she’s had a really tough few years so I’m doing this is for her as well. Bring it on."
Mellor told hosts Naga Munchetty and Charlie Stayt that Strictly was his mother Shirley’s favourite show and that following the death of his father in 2020 he wanted to create new memories.
He said: “The training side of it is one of the reasons why I’m doing it. My mindset completely changed a while back and I just thought I’ve got to start doing things that frighten me a little bit and step out of your comfort zone, and that’s what life is about.
“And when I got the phone call for this I just said ‘yes, I’m going to do it’.
“Also I lost my dad in 2020 and I just thought from then I’ve just got to grab life and I’ve got to do things and I’ve got to create new memories and my mindset changed, and that’s sort of one of the reasons why.
“It’s my mum’s favourite show, so she’s had it really tough over the last few years so I thought we’ll do this.”
Mellor’s father Bill died in April 2020 after being diagnosed with cancer two weeks earlier.
He later posted a video on Instagram, saying he had had “the worst week of my life”, but that he intended to “remember the good times”.
Mellor said his mother had also lost three other close family members including her brother during 2020 to Covid and other illnesses.
“It is something we can do together, get on the Strictly train together,” he added.
The soap star said he had asked permission from his two children before accepting the BBC’s offer to appear on the show.
He said: “I had to tell my kids because I had to ask them if it was alright. You know what it is like when you have got kids.
“My son is 18, my daughter is 14 now. If they are going to be mortified then I am not going to do anything that they are going to go ‘please dad, don’t do it’.
“They are OK.”
Four new professional dancers will appear in the next series of Strictly, creating the show’s largest ever roster.
It comes after two-time winner Oti Mabuse and Aljaz Skorjanec announced their departures.