The rocker is said to have met Goulding recently while they were both touring in Australia, and editors at British newspaper The People report they have grown close.
A source tells the publication, "Ellie and Nate were both in Brisbane where they were gigging and they met. They instantly got on really well and arranged to meet up again. They have been out together a few times now and Ellie really likes him. They were seen in Brisbane looking really happy, they were laughing and touching one another very affectionately."
Ruess has previously spoken of his admiration for Goulding, picking her as his perfect collaboration partner, saying, "I'm like such a big fan of that last album. Hopefully maybe she and I will get the chance to work together some time soon."