Super Tuesday 2008, Super Duper Tuesday, Mega Tuesday, Giga Tuesday, Tsunami Tuesday, and The Tuesday of Destiny are names for February 5, 2008, the day on which the largest simultaneous number of state U.S. presidential primary elections in the history of U.S. primaries were held. Twenty-four states and American Samoa held either caucuses or primary elections for one or both parties on this date. Furthermore, the week-long Democrats Abroad Global Primary began on this day.

The 2008 Alaska Democratic presidential caucuses took place Super Tuesday, February 5, 2008. This was the first time that Democrats in Alaska participated in Super Tuesday, and the large turnout forced at least one caucusing site to delay closing its doors far beyond the 6 p.m. deadline. The state had a total of 13 delegates at stake. Barack Obama won the Alaska Democratic Caucuses and secured 9 delegates to the Democratic National Convention while Hillary Clinton took 4 delegates. However, the caucus was non-binding, and Alaska's Democratic State Convention in May awarded Obama 10 pledged delegates.