According to People.com, the couple has "gone their separate ways", although reasons for their break-up have yet to be revealed. Representatives for the pair have not commented on the reports.
Dylan and Maggie first met on the set of TV show "Stalker", and sparked rumours of a romance in September 2014. They made their red carpet debut as a couple at the Golden Globes in January 2015, where Maggie was spotted wearing an engagement ring. According to reports, Dylan popped the question to his co-star just seven weeks after they started dating.
After going public with their engagement, Maggie and Dylan were indundated with questions about when they'd tie the knot at various red carpet events, with the Hawaii-born actress admitting in March 2015 that their careers were making it hard to settle on a date.
"So, yeah, (it's) because of work, and... because you gotta balance everything," she said at the time.
It's been a difficult few weeks for Maggie, who took to Instagram last month to reveal one of her beloved dogs had died. Sharing a picture of herself with the pooch, Maggie wrote: "I would do anything to have you back. (broken heart emoji) Anything."
Neither Maggie nor Dylan have commented on the split rumours on their social media pages.
Dylan was previously married to actress Shiva Rose from 1995 to 2009.