The event will be the third year in a row that Shawn - who is nominated for five awards - has performed at the ceremony, having previously sung "There's Nothing Holdin' Me Back" in 2017 and "In My Blood" last year.
Camila - who won two Moonmen last year and is up for four at the 2019 ceremony - will be making her VMAs performance debut, as will all of the other newly-announced artists, including Lizzo, Lil Nas X, Bad Bunny, J Balvin and Rosalia.
Meanwhile, Camila, 22, recently took to Instagram to wish her boyfriend and collaborator a happy 21st birthday, and also used the sweet moment to declare her "love" for him publicly for the first time.
She wrote alongside a picture of the pair: "Happy birthday to this magic human, I love you!!!! (sic)"
Camila's post also included four love heart emojis, and came just days after she revealed the 'In My Blood' singer - whom she has been spotted packing on the PDA with on numerous occasions - "means a lot" to her.
She said: "I've known Shawn for such a long time, and it's so much fun getting to work and do things with somebody who means a lot to you."
But although she's loving spending quality time with her new beau, she "honestly hates" seeing paparazzi snapping photos of the two of them enjoying a romantic kiss, especially when she doesn't know the photos are being taken.
She added: "It makes me insanely uncomfortable to see pictures of me that I didn't know were taken. I honestly hate it. I don't want to live like a celebrity and have to look perfect every time I step out of my house. I ignore it as much as possible.
"If I'm going to look like s**t that day and cameras are in my face, I don't care because I choose being human and normal."
Meanwhile, it was previously claimed the happy couple have "really fallen for each other".
A source said: "Shawn and Camila originally were just enjoying spending time together and having a summer fling. Camila had just got out of a relationship and Shawn was in the middle of a massive tour.
"However, Shawn and Camila have really fallen for one another."