The album was produced by David Bendeth. Lead vocalist Hayley Williams explained the album was called Riot! because "For us, the title ‘Riot!’ literally means an unbridled outburst of emotions. When we were writing, it seemed like our thoughts and emotions were coming out so fast that we couldn't control them. It felt like there was a riot within us. So the album takes our passion to a new level; it’s just all raw energy."

The track "For a Pessimist, I'm Pretty Optimistic" comes from what lead guitarist Josh Farro reflects as "putting your faith in someone and they blow it." Farro composed the song and gave the demo to Williams. Farro is known as saying "I wrote the music specifically to be awesome live and to be extremely energetic. It all came out at once. I showed it to Hayley and she just nailed it lyrically. She completely got the feeling I wanted the song to have."

During production, Paramore held an online contest entitled "The Last Song You'll Ever Sing" where fans submitted videos on Youtube for the opportunity to sing back-up vocals on the track "Born for This". The winner was Mary Bonney of McLean, Virginia. On "That's What You Get", Steven from Steven's Untitled Rock Show is featured and is credited. The band asked him when he went to the studio.

The album has yielded four singles, with "Misery Business" being the first. Its origins came from a message Williams posted on the band's LiveJournal, asking fans to post what they're ashamed of. "I found that people really were reaching out to someone to spill their guts to," she recalls, "so I did the same thing lyrically in the song and let everything out. It's more honest than anything I've ever written, and the guys matched that emotion musically." The song became an instant hit, eventually receiving heavy rotation on MTV and other music television networks.

The album's second single was "Hallelujah". As Williams recounts, "It's one of the oldest songs we've got, but we wanted to save it for this record, and it's the perfect home for it. It's a claim of victory for both ourselves and our fans."

The album's third single was "Crushcrushcrush" and was released January 15, 2008, in the US and the January 23 in the UK.

The album's fourth single, "That's What You Get", was released just over a week after Paramore canceled their European tour to work on "personal issues", amidst media speculation of the band breaking up. Williams explained that, given the fragile state of the band, they all thought it best if they kept the shoot low-key, surrounding themselves with their friends and family, keeping it simple. Williams added, "We had tons of friends there, and it really just felt like a hangout session. And Marcos [Siega, the director] was so cool about it. He said, 'Bring your friends.' We shot it in some of our friends' houses, and it just felt so real... and I think it's the first time in a video you're gonna get to see who we really are."

The track "Born for This" contains elements from the song "Liberation Frequency" taken from the album The Shape of Punk to Come by the influential Swedish hardcore band Refused.

Riot! was released in the United States on June 12, 2007, following the debut of "Misery Business" on the radio. It entered the U.S. Billboard 200 charts at 20 in late 2007. Riot! sold 42,000 albums in the U.S. in its first week and three months later the album hit its peak at 15 on the Billboard 200. The album achieved some success in the UK reaching #24 on the albums chart. The album was certified Platinum on July 11, 2008. The hit single "Misery Business" has also been certified Platinum by the RIAA. The album was re-released in late 2007 as a U-MYX MVI CD/DVD. The album has so far sold 1,196,000 copies in the U.S. In New Zealand, the album peaked at number 15, and was certified Gold on February 1, 2009, selling over 7,500 copies.

Critical opinion for Riot! was mixed. Some critics gave the album positive reviews; Jason Lymangrover of Allmusic gave the album 3.5 out of 5 stars and commented that, "Ultimately, this disc has enormous crossover potential, and will probably appeal to those who are fans of the genre, and for those who aren't, there's a good chance of it becoming a guilty pleasure." Stylus Magazine gave the album a B+ and said, "Riot! is immediately appealing because it focuses on sounds that have been neglected by the genre's front-runners. This is an uncomplicated album comprising of strikingly uncomplicated music, entirely lacking in 15 word song titles."Gareth Dobson of Drowned in Sound gave the album 4 out of 10 stars and said, "At 38 minutes long, it's mercifully brief, but still manages to feel like a double album for those who endure it. That is, those who don't manage to forget that it's on the stereo at all. People, get your pop-punk thrills somewhere else. At least somewhere where there are actual thrills to be had." Despite mixed and lukewarm reviews, Riot! found itself in several "must have" lists that were compiled by various music publications, networks and other media.

Williams said, "We're hoping to do one more tour across the States before we really get started with all the (European summer) festivals. Of course, I want to do more Warped Tour dates, 'cause it's, like, my favorite tour ever. We'll see what works out and hopefully just have another great year."

After the album release the band went on an American tour, following it up with a world tour. After their fourth single from Riot! was released the band canceled their European tour to work on "personal issues."