Hamilton was born in New York City 1969. His father is actor Dan Hamilton, and his stepmother is actress Stephanie Braxton. His Broadway credits include Proof and The Coast of Utopia (2007, Lincoln Center). He is know for: J. Edgar, Ice Age, Dark Skies and The Bornue Identity. In his life Josh won 1 award ( Daytime Emmy - 1992)
Hamilton performed in The Cherry Orchard at the Brooklyn Academy of Music in January and February 2009, alongside Ethan Hawke, who was his co-star in the 1993 film Alive. On Thursday, November 18, 2010, it was announced that both Hamilton and Dane Cook will be starring in Neil Labute 's Fat Pig. This will mark the Broadway directorial debut of Labute. In 2011 Hamilton starred as Torvald in Henrik Ibsen's A Doll's House at the Williamstown Theatre Festival. Hamilton has also performed on PRI's Selected Shorts, reading Neil Gaiman's story The Thing About Cassandra.