The 2012 Oklahoma Democratic presidential primary took place on Tuesday, March 6, 2012, as part of Super Tuesday along with other primaries and caucuses. Oklahoma's 45 pledged delegates to the Democratic National Convention were allocated according to the results of the vote.

The 2008 Oklahoma Democratic presidential primary, part of the process of selecting that party's nominee for President of the United States, took place on February 5, one of the many nominating contests of 2008's "Super Tuesday". The primary election chose 38 pledged delegates to represent Oklahoma at the 2008 Democratic National Convention. The remainder of Oklahoma's 47 delegates consisted of unpledged superdelegates not bound by the results of the primary. The election was a closed primary, meaning that only registered Democrats could vote in this election. Hillary Clinton won the primary by a significant margin.