The 31-year-old will be seen on the BBC One drama in a few months' time as manipulative criminal Steve-O Malone.
Steve-O is an ex-con who has history with current character Dynasty Barry (Abby Mavers) as they used to be in a relationship.
While further storyline details have not been disclosed, show bosses are tipping Steve-O's arrival to "rock the foundations of Waterloo Road".
Latham will make his Waterloo Road debut in the third instalment of the eighth series (episodes 21-30), which is scheduled to transmit on BBC One later this year.
The actor is best known for playing villain Rob Grayson in EastEnders and Phillip 'Lip' Gallagher in Shameless.
Waterloo Road airs on Thursdays at 8pm on BBC One. Get the Inside Soap magazine on your iPhone or iPad