The young couple have grown close on the set of 'The Mortal Instruments: City of Bones', and now that filming is well underway they are proving to be inseperable.
Stepping out in matching outfits on Thursday night, the pair attended a gallery party in Toronto.
Looking relaxed in each other's company, the 23-year-olds left the venue keeping warm in matching jeans and black coats. Lily couldn't stop smiling, she was clearly happy to be spending time with her boyfriend away from the film set.
The pair are currently working on a teenage drama about a girl whose mother is attacked and taken away by a demon. On Clary Fray's quest to get her back she discovers truths about her past and bloodline that change her life forever.
"It's really a story that's based in reality as much as it is in this fantasy world. They're coexisting," Lily told MTV.
"It's more emotionally and character-based than just aesthetically beautiful. It's got amazing imagery and the CGI is going to be incredible, but it's not just about that."
Jamie is well-known for his roles in Harry Potter and Twilight, both films have a similar fantasy element to this latest project. He is also known for dating co-stars and was even engaged to Bonnie Wright, who played Ginny Weasley in Harry Potter, until they split in July.
Lily has similarly been linked to her 'Abduction' co-star Taylor Lautner, but has also been linked to Zac Efron.
However, the latest snaps of the duo suggest they only have eyes for each other, having been spotted in various locations around the city making the most of each other's company while they haven't been working.
Lily Collins brings the style factor in New YorkOne Direction's Harry Styles Talks Teenage Issues: 'I Wear More Spot Cream Than My Mum'
Khloe Kardashian Odom Thinks That 'Kanye West Is Too Domineering For Kim Kardashian'
Taylor Swift Accused Of Stealing Song Lyrics From Folk Singer