As a true freshman, Okung moved into the starting lineup for the first time against Kansas and held the position of right tackle for the rest of the season (eight straight starts). He ended the season by being voted as a member of All-Big 12 freshman team (by The Sporting News) and was named the Dick Bogert Award winner as Oklahoma State’s top freshman.
In his sophomore season he started all thirteen games. The Cowboys’ offensive line gave up just five sacks in eight Big 12 games to lead the league in that category. Okung earned honorable mention all-Big 12 honors (by coaches). He was also named to the Rivals.com all-bowl team after holding Indiana’s Greg Middleton, the NCAA’s sack leader, without a tackle in the 2007 Insight Bowl victory.
As a junior, Okung led Oklahoma State with 71 knockdown blocks, and was named a first-team all-conference selection by the coaches. He also was named to Pro Football Weekly′s 2008 All-America team. Okung currently has started 34 straight games for the longest active streak on the team.
In 2009, Okung was listed at No. 1 on Rivals.com′s preseason offensive tackle power ranking. He was also named to the 2009 Outland Trophy watch list. On October 14, 2009, Okung was named one of twelve semifinalists—and the only offensive lineman—for the Lombardi Award. He was also named to The Sporting News midseason college football All-American team.
In a game against Texas A&M on October 10, Okung held the current NCAA sack leader, Von Miller, without a quarterback sack. That effort was the second time during his career he has not allowed a sack against the nation’s leader at the time. Against Texas on October 31, Okung held the Longhorn pass rush, including All-American candidate Sergio Kindle, without a quarterback sack. According to Sports Illustrated’s Tony Pauline, that performance “has solidified his projection as the top senior tackle” in the 2010 NFL Draft. On November 24, 2009, Okung was named one of three finalists for the 2009 Outland Trophy, alongside Mike Iupati and Ndamukong Suh.
On December 1, 2009, Okung was named Big 12 Offensive Lineman of the Year in a vote of the league’s coaches. He also received unanimous 2009 All-American honors. Despite tweaking his knee in practice earlier that week, Okung played in the 2010 Cotton Bowl Classic to end his career at Oklahoma State with a streak of 47 straight starts.
 Professional career
 2010 NFL Draft
Okung is considered one of the best offensive tackles available in the 2010 NFL Draft, and draws comparisons to D’Brickashaw Ferguson. According to NFL.com’s Gil Brandt, Okung “will start and play a lot of years in the NFL.” NFL.com’s Bucky Brooks even projects Okung as the No. 1 pick overall, as does Scout.com′s Chris Steuber. Sports Illustrated′s Tony Pauline described Okung as “a complete offensive tackle with a large upside,” who “stands out in pass protection while also dominating as a run blocker”. The Kansas City Chiefs are believed to be one of the NFL teams to target Okung in the draft, as well as the Washington Redskins. He could be only the second Oklahoma State offensive lineman ever picked in the first round of an NFL Draft, along with John Ward, who was selected 25th overall by the Minnesota Vikings in 1970, and the highest OSU draft pick since Barry Sanders went 3rd overall in the 1989 NFL Draft.