Izturis, a 32-year-old native of Barquisimeto, Venezuela, appeared in 100 games for the Los Angeles Angels last season. He posted a .256 average with two home runs, 20 RBIs and 17 stolen bases in 19 attempts.
The Blue Jays said the deal was for $3 million annually. The contract includes a $3-million team option for the 2016 season with a $1-million buyout.
Izturis spent eight years with the Angels after breaking into the majors in 2004 with the Montreal Expos. In 791 career games, the five-foot-eight, 175-pound switch-hitter has a .273 average and a .337 on-base percentage while splitting time primarily between second base, third base and shortstop.
Jeffress, a 25-year-old native of South Boston, Va., did not record a decision in 13 relief appearances for the Royals last season. The six-foot, 195-pounder allowed 19 hits over 13 1/3 innings and posted a 6.75 earned-run average.
Over parts of three seasons with the Royals and Milwaukee Brewers, Jeffress has two wins, one loss, one save and a 4.89 ERA in 37 big-league appearances.
The Blue Jays also designated left-hander Scott Maine for assignment to make room on the 40-man roster.