OUAT may refer to:

• Once Upon a Time (disambiguation)
• Orissa University of Agriculture and Technology, a public Indian agricultural university
• Once Upon a Time (TV series)

• Australia at the 1964 Summer Paralympics
• Australia at the 1968 Summer Paralympics
• Australia at the 1972 Summer Paralympics
• Australia at the 1976 Summer Paralympics
• Australia at the 1976 Winter Paralympics
• Australia at the 1980 Summer Paralympics
• Australia at the 1980 Winter Paralympics
• Australia at the 1984 Summer Paralympics
• Australia at the 1988 Summer Paralympics
• Australia at the 1988 Winter Paralympics
• Australia at the 1992 Summer Paralympics
• Australia at the 1992 Winter Paralympics
• Australia at the 1994 Winter Paralympics
• Australia at the 1996 Summer Paralympics
• Australia at the 1998 Winter Paralympics
• Australia at the 2002 Winter Paralympics
• Australia at the 2004 Summer Paralympics
• Australia at the 2008 UCI Track Cycling World Championships
• Australia at the 2011 Commonwealth Youth Games
• Australia at the 2011 World Aquatics Championships
• Australia at the 2011 World Championships in Athletics
• Australia at the 2012 Summer Paralympics
• Australia at the 2012 Winter Youth Olympics
• Australia at the 2013 Summer Universiade
• Australia at the 2013 Winter Universiade