He played three years of college basketball for Nevada, earning WAC All-Newcomer Team as a freshman and second-team All-WAC as a junior.

Sessions was named South Carolina 3A State Player of the Year three times while attending Myrtle Beach High School.

[1] He made his NBA debut on March 9, 2008, recording two points, two assists and one steal in just over four minutes off the bench in a 119–97 loss to the Philadelphia 76ers.

He handed out double-figure assists in five straight games to end the season and was subsequently named Eastern Conference Rookie of the Month for April.

He scored a career-high 44 points and handed out 12 assists on February 7 against the Detroit Pistons, setting career highs of 13 field goals, 18 free throws and 21 free-throw attempts.

He recorded his lone career triple-double with 16 points, 16 assists and a career-high 10 rebounds on April 1 against the Los Angeles Lakers.

[1] On July 26, 2010, Sessions was traded, along with Ryan Hollins and a future second-round draft pick, to the Cleveland Cavaliers in exchange for Delonte West and Sebastian Telfair.

[11] In 2010–11, Sessions appeared in 81 games (38 starts) for the Cavaliers, averaging a career-high 13.3 points, 5.2 assists and 3.1 rebounds in 26.3 minutes.

[1] On February 8, 2012, Sessions recorded a season-high 24 points and 13 assists in the Cavaliers' 99–92 win over the Los Angeles Clippers.

[13] On March 15, 2012, Sessions was traded, along with Christian Eyenga, to the Los Angeles Lakers in exchange for Luke Walton, Jason Kapono, a protected 2012 first-round draft pick, and other considerations.

[1] On February 20, 2014, Sessions was traded, along with Jeff Adrien, to the Milwaukee Bucks in exchange for Gary Neal and Luke Ridnour.

[30] On November 3, 2018, Sessions joined the Israeli team Maccabi Tel Aviv of the EuroLeague, signing a three-month contract with an option to extend it for the rest of the season.