Has the nickname Stinky (for having a snarky attitude in college, not because of hygiene.)
He wrote a screenplay titled Stoker, which was released as a feature film starring Nicole Kidman, Mia Wasikowska and Matthew Goode in early 2013. He also wrote The Disappointments Room starring Kate Beckinsale, which was released in 2016.
A nice, friendly guy, he talks often about how grateful he is for the doors that have opened to him from working on Prison Break. In August 2013, Wentworth declined an invitation to a Russian Film Festival in protest of the country's anti-gay laws, saying "As someone who has enjoyed visiting Russia in the past and can also claim a degree of Russian ancestry, it would make me happy to say yes [...] However, as a gay man, I must decline."
In 2014, he began recurring as Leonard Snart / Captain Cold across the Arrowverse, starting on The Flash, eventually joining its 2016 spinoff, Legends of Tomorrow, in a leading role.
He has an Instagram account that he used to post to fairly regularly (mostly photos of art and graphic design that he found interesting). Initially, he was forced to disable commenting on it multiple times due to homophobic trolling and people constantly begging him for more Prison Break - to the point where you could click on any post and 99% of commenters would be referring to him by his character's name - despite him repeatedly saying he was done with the show; some time in 2020 he deleted most of it altogether. He did have a Facebook page but deleted it in 2018, citing unhappiness with what it had become and the liberties people were taking.
One of the few things he did post on Instagram after deleting most of it came in July 2021 when he revealed he'd been officially diagnosed as autistic, in a (now-removed) heartfelt post reflecting on his journey to diagnosis and his feelings on both his own autism and his place in the autistic/neurodiverse community. As of 2023 the post (and his social media in general) has been hidden/removed, although Miller occasionally reactivates it for short periods of time, he prefers to remain private.
- Dinotopia (2002) as David Scott
- Underworld (2003) as Dr. Adam Lockwood
- Prison Break (2005 – 2009, 2016) as Michael Scofield
- Stealth (2005) as the voice of EDI
- Resident Evil: Afterlife (2010) as Chris Redfield
- Young Justice (2010) (2013) as Slade Wilson / Deathstroke
- Stoker (writer; 2013)
- The Loft (2014) as Luke Seacord
- Arrowverse (2014 – 2021) as Leonard Snart / Captain Cold and Citizen Cold:
- The Flash (2014) (2014 – 2015, 2019)
- Legends of Tomorrow (2016-2018; 2021)
- Crisis on Infinite Earths (2019) (2019) as the voice of Earth-74 Waverider's AI
- The Disappointments Room (writer; 2016)