Former Off the Map star Gummer wore her grandmother's gown when she tied the knot with Walker over the weekend at the Streep family home in Connecticut.
Claire Daines, Tracey Ullman and Laura Linney were among the 150 guests who attended the pair's lakeside nuptials, according to The Washington Post.
The couple met while starring in the 2008 Broadway production of Dangerous Liaisons and dated for more than 18 months before announcing their engagement in 2009.
Gummer's upcoming film The Ward is released in US cinemas on August 16.
Walker will next appear in Abraham Lincoln, Vampire Hunter, which is expected to open in summer 2012.
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