Hornak, Mark R., 1956-

Mark Raymond Hornak (born March 31, 1956) is the Chief United States District Judge of the United States District Court for the Western District of Pennsylvania.

Born on March 31, 1956 in Homestead, Pennsylvania, Hornak earned a Bachelor of Arts degree in 1978 from the University of Pittsburgh and a Juris Doctor in 1981 from the University of Pittsburgh School of Law. From 1981 until 1982, he served as a law clerk to Judge James Marshall Sprouse of the United States Court of Appeals for the Fourth Circuit, in Charleston, West Virginia.

On December 1, 2010, President Obama nominated Hornak to fill a judicial vacancy on the United States District Court for the Western District of Pennsylvania that had been created by the transition to senior status in November 2010 by Judge Donetta Ambrose. The United States Senate confirmed Hornak in a voice vote on October 19, 2011. He received his commission that same day. He became Chief Judge on December 7, 2018.