The British singer has been in a relationship with the producer - who won three Grammy Awards last Sunday (12.02.12) - since the end of last year, after they worked together on his track 'Summit'.
A source told The Sun newspaper: "Ellie and Skrillex are fans of each other's music and met at the end of last year.
"They hung out in the studio as Ellie was featuring on his EP 'Bangarang' and they got on really well.
"It has blossomed into something more than Friendship, but it is still early days."
Ellie was dating Radio 1 DJ Greg James until late last year, when she was spending a lot of time in the US and was introduced to Skrillex - real name Sonny Moore - through industry contacts.
She has reportedly kept her new romance under wraps to avoid hurting Greg.
Another source told Us Weekly magazine: "It's a really cool new romance and they get along perfectly.
"They're really good together. Everybody thinks it's awesome. Both of them are so talented. It's a great Los Angeles romance for her now that she hasn't been in London."
While Skrillex is one of the hottest new names in dance music, Ellie had a hit in the UK with her version of Elton John's 'Your Song', and was personally invited to perform at the wedding of Prince William and Duchess Catherine.
Possibly alluding to Skrillex in a previous interview she has said: "It makes all the difference what producer you're working with.
"The other day I just found somewhere where it was like, it clicked in my brain that I wanted to work with that person. And I won't say who it is but I think it could be awesome if I end up doing stuff with him."