On Feb 1,, Tolleson was claimed off waivers by the Oakland Athletics. He made his big league debut with the A's on April 28 against the Toronto Blue Jays. Two days later, he picked up his first major league hit against Josh Roenicke of Toronto.
On November 21, 2011, Tolleson signed a contract with the Baltimore Orioles. On May 9, 2012, the Orioles purchased Tolleson's contract and called him up. He hit.183 in 71 at-bats over several stints. After the season, he was outrighted off the Orioles' 40-man roster but refused the assignment and elected free agency.
On November 13, 2012, Tolleson signed a minor league deal with the Chicago White Sox with an invitation to spring training. He spent the season with the Triple-A Charlotte Knights.
On December 17, 2013, Tolleson signed a minor league deal with the Toronto Blue Jays that included an invitation to spring training. He was sent to minor league camp on March 24, 2014. The Blue Jays selected his contract from the Triple-A Buffalo Bisons on May 1. He made his debut for the Jays the following day, and recorded a pinch-hit triple and an RBI against the Pittsburgh Pirates. The triple was the first of his Major League career. On May 14, Tolleson pitched for the first time in the Majors, getting the final out in a 15–4 loss to the Cleveland Indians. In pitching for the Blue Jays, he became just the seventh position player to do so for the franchise, and first since Jeff Mathis in 2012. Tolleson hit his first home run as a Blue Jay on May 23, helping the team to a 3–2 win over the Oakland Athletics. He played in 109 games for the Blue Jays in 2014, mostly as a pinch hitter and late-innings replacement, and hit.253 with 3 home runs and 16 RBI. Tolleson opened the 2015 season as the backup infielder for the Blue Jays. On April 24, 2015, he was designated for assignment to make room on the roster for Michael Saunders. He cleared waivers on May 5, and was assigned to the Triple-A Buffalo Bisons, but chose to become a free agent. On May 7, Tolleson signed a new minor league contract with the Blue Jays, allowing him to bypass a 10-day waiting period before he could be recalled to Toronto. On May 10, Tolleson was re-added to the active roster, after Michael Saunders was placed on the disabled list. He suffered a groin injury in late May and was placed on the disabled list. On July 1, Tolleson was activated from the disabled list and designated for assignment for the second time in 2015. He remained in the minors through the end of the season. Tolleson appeared in 19 games for the Blue Jays in 2015, and batted.268 with 3 RBI. He elected free agency on October 5, 2015.
Second stint with Baltimore
On November 23, 2015, Tolleson signed a minor league contract with the Baltimore Orioles that included an invitation to spring training. He was released on May 24, 2016.
