The seven-year CFL veteran joins the Lions after sitting out the 2013 campaign. He last suited up for the Edmonton Eskimos in 2012, starting nine games with a 5-4 record.
"Steven has a lot of experience in our league as both a starter and a back-up and we expect him to provide a significant level of competition for the quarterbacks we have under contract," B.C. general manager and vice-president of football operations Wally Buono said in a statement.
Jyles has dressed for 114 regular season games, 28 as a starter, with Edmonton, Saskatchewan, Winnipeg and Toronto. He has thrown for a career 7,075 yards on 541 completions with 37 touchdowns. He's also added 1,296 rushing yards on 197 carries with 13 touchdowns.