'Euphoria' Star Sydney Sweeney Seemingly Engaged, Wears Huge Diamond Ring

"Euphoria" star Sydney Sweeney looks like she's taken ... wearing a huge rock on her ring finger, in what can only be assumed to be an engagement ring.

It's hard to miss the flashy diamond ring Sydney's rocking on THAT finger ... check out the pics of Sydney chatting up a friend Monday in Los Angeles, the new bling really stands out.

Sydney's not only debuting a new ring ... but also some red hair. So, two really big life changes here.

It's the first time Sydney's been seen with the diamond ring, she's continuously remained mum on her relationship with her likely new fiancé -- Jonathan Davino. Davino's family owns 14th Round and Finalbell ... a device technology and packaging company.

The couple reportedly started dating back in 2018 -- though Sydney's never confirmed their relationship -- but they've been linked and were even photographed together last summer smooching on a yacht.

Sydney, who stars as Cassie on HBO's "Euphoria" and Olivia on "The White Lotus"
is 24 years old ... Jonathan is reportedly 37.

This would be her first marriage.