The singer was enraged at the attack at the Manchester M.E.N. Arena, which saw 22 people killed and 59 injured after a bomb went off at an Ariana Grande concert on Monday (22 May) night.
Taking to the stage in Detroit just hours after the bombing, Matt, who grew up in Greater Manchester, raged against religion and nationalism.
Speaking to the crowd as he paced across the stage, he said: “I’m f***ed off. I’m bored of nationalism and I’m bored of racism.”
“It’s over. Nationalism, religion, all these regressive things, they’re over. We can’t carry on in the way that we’re carrying on.
“We’re from Manchester and where we used to hang out, the actual place where we used to hang out, someone put a bomb in there tonight and then killed a bunch of kids that were going to a f***ing show.”
Matt - the son of actors Denise Welch and Tim Healy - continued: “I don’t need to be educated on fucking anything to say that that is bullshit.
“I don’t know what it’s in the name of, so I apologise if it’s not in the name of religion or nationalism, but these are things that keep happening and I’m fucking pissed off about it.”
Ariana Grande said she was “broken” in a tweet posted in the early hours of Tuesday morning following the attack, adding: “From the bottom of my heart, i am so so sorry. i don’t have words.”
She has since reportedly postponed the European leg of her world tour “indefinitely”.
Stars including Katy Perry, Harry Styles, Taylor Swift, Gary Barlow and Nicki Minaj also paid tribute to the innocent victims on their social media accounts, while ‘Good Morning Britain’ host Susanna Reid broke down in tears while covering the story earlier in the show.