The Desperate Housewives actress joins 35 politicians, business professionals and celebrities in helping to organise Obama's election strategy.
Kal Penn - who has previously worked in the Obama administration's Office of Public Engagement - will also take time away from How I Met Your Mother to campaign for Obama.
Massachusetts Governor Deval Patrick, Rhode Island Governor Lincoln Chafee and Illinois Senator Dick Durbin are among the politicians named as Obama's organisers.
The chief role of these co-chairs will be to meet with voters and publicise Obama's re-election platform, according to the president's campaign.
Longoria has been involved in a variety of political causes in recent years, including advocating the creation of a National Museum of the American Latino.
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Watch Eva Longoria discuss her support for Barack Obama below: