The 'Starry Eyed' singer will play London's Roundhouse on September 26, while One Republic will perform on September 19 with Matchbox Twenty.
"I am really, really happy to be playing the iTunes Festival this year," Goulding said. "I played it once before and it genuinely was one of my favourite shows ever.
"The Roundhouse is a special venue and it's awesome that people can watch from home and that the show is free. This will be my first UK show in a long time, so I'm both extremely nervous and excited. Thanks iTunes!"
Each gig will be streamed live via iTunes, with tickets available by prize draw through the festival's website.
The lineup for the iTunes Festival so far is as follows:
Usher (September 1)
Ed Sheeran, Charli XCX (2)
Olly Murs, The Milk (3)
Emeli Sandé, Bastille (5)
Plan B (5)
JLS, Conor Maynard (6)
Elbow, Bat for Lashes (7)
Jack White, Band of Horses (8)
Norah Jones (10)
Noel Gallagher's High Flying Birds, The Soundtrack Of Our Lives (12)
Pink, Walk the Moon (13)
Labrinth, Josh Kumra (14)
David Guetta, Calvin Harris (15)
Rebecca Ferguson (16)
Example, DJ Fresh, Hadouken! (17)
Andrea Bocelli (18)
One Republic, Matchbox Twenty (19)
One Direction (20)
Jessie J, Lonsdale Boys Club (21)
Biffy Clyro, Frightened Rabbit (22)
Robert Glasper (23)
Mumford & Sons (24)
Lana Del Rey (25)
Ellie Goulding (26)
Hot Chip (29)