Severine Howell-Meri, Cherelle Skeete and newcomer Gianna Kiehl have also joined the new season which will once again feature Esme Creed-Miles in the title role along with Mireille Enos as CIA operative Marissa Wiegler.
Hanna, based on the 2011 film of the same name by director Joe Wright, follows a talented and resourceful young girl on the run from the CIA and the shadowy Utrax organization.
Mulroney (Homecoming, My Best Friend's Wedding) is set to portray John Carmichael, a former mentor of Marissa's who will head a new chapter of Utrax. Welsh (Fleabag, Black Mirror) will be seen as Leo Garner, who works for Utrax's operations team.
Filming has started on Hanna Season 2 in the U.K. and France. The first season premiered on Amazon's Prime Video streaming service on March 29.
David Farr who co-wrote the original film and penned the first eight episodes of Season 1, is returning as a writer, executive producer and director. Eva Husson and Ugla Hauksdottir are also serving as directors.