https://www.cnet.com/news/game-of-thrones-jorah-mormont-to-play-bruce-wayne-on-titans/

You might recognize Glen from his turn as Jorah Mormont from Game of Thrones, where he plays a knight who pledged his loyalty to Daenerys Targaryen. 

According to Deadline, Glen will play an older Bruce Wayne and it's not clear if he'll be wearing the bat suit at any point.