Timothy Blake "Tim" Nelson (born May 11, 1964) is an American actor, writer, and director. His most famous roles include Delmar O'Donnell in O Brother, Where Art Thou? (2000), Dr. Pendanski in Holes (2003), Daniel "Danny" Dalton Jr. in Syriana (2005), Dr. Samuel Sterns in The Incredible Hulk (2008), Richard Schell in Lincoln (2012), Buster Scruggs in The Ballad of Buster Scruggs (2018), and Wade Tillman / Looking Glass in the HBO series Watchmen (2019) for which he was nominated for a Critics' Choice Television Award.
Nelson was born to a Jewish family in Tulsa, Oklahoma, the son of Ruth (née Kaiser) Nelson, who is a noted social activist and philanthropist in Tulsa, and Don Nelson, a geologist and wildcatter. His maternal uncle is businessman George Kaiser.
His maternal grandparents Herman Geo. Kaiser and Kate Kaiser, daughter of businessman Max Samuel, who were from Germany, escaped the Nazis shortly before World War II, moving to Britain in 1938, where Nelson's mother was born, and immigrating to the United States in 1941. His father's family were Russian Jewish emigrants.