Katy Perry's Manchester concert dress included a beautiful tribute to the victims.

The One Love Manchester concert was full of beautiful tributes to the 22 victims of the deadly bombing at Ariana Grande’s Manchester concert on May 22.

From Grande herself singing with a local school choir, to the one-minute silence that ended in a roar of cheers to commence the concert, it was a spine-tingling occasion.

But there was one reference to those who lost their lives in the attack that you might have missed.

Click through for more highlights of One Love Manchester. (Post continues.)

As we watched Katy Perry perform heartfelt renditions of Part of Me and Roar we overlooked a touching detail on her outfit.

As Twitter users later pointed out, the back of Perry’s dress featured photos of the 22 victims in the shape of a heart, which we could see when she shed her fluffy coat.

It’s a small gesture on top of the generosity of her and other stars giving up their time to perform, and we’re sure it was appreciated by the families of those lost.

Fans were certainly moved, sharing their love for the dress on Twitter.

The One Love Manchester concert raised more than $3.4 million for the We Love Manchester Emergency Fund to help victims of the attack.

The One Love Manchester will be rebroadcast tonight on Channel Nine at 8.45pm AEST.