| Donald Emil Ziegler | |
| Office: | Senior Judge of the United States District Court for the Western District of Pennsylvania |
| Term Start: | October 1, 2001 |
| Term End: | May 31, 2003 |
| Office1: | Chief Judge of the United States District Court for the Western District of Pennsylvania |
| Term Start1: | 1994 |
| Term End1: | 2001 |
| Predecessor1: | Gustave Diamond |
| Successor1: | D. Brooks Smith |
| Office2: | Judge of the United States District Court for the Western District of Pennsylvania |
| Term Start2: | May 2, 1978 |
| Term End2: | October 1, 2001 |
| Appointer2: | Jimmy Carter |
| Predecessor2: | Rabe Ferguson Marsh Jr. |
| Successor2: | Terrence F. McVerry |
| Birth Name: | Donald Emil Ziegler |
| Birth Place: | Pittsburgh, Pennsylvania |
| Death Place: | Pittsburgh PA |
| Education: | Duquesne University (BA) Georgetown University Law Center (LLB) |
Donald Emil Ziegler (October 1, 1936 – September 21, 2019) was a former United States district judge of the United States District Court for the Western District of Pennsylvania.
Born in Pittsburgh, Pennsylvania, in 1936, Ziegler received a Bachelor of Arts degree from Duquesne University in 1958, and a Bachelor of Laws from Georgetown University Law Center in 1961, where he was a member of the Law Review. He was in private practice in Pittsburgh from 1962 to 1974. He served as a judge of the Court of Common Pleas, Allegheny County, Pennsylvania, from 1974 to 1978.
On March 22, 1978, Ziegler was nominated by President Jimmy Carter to a seat on the United States District Court for the Western District of Pennsylvania vacated by Judge Rabe Ferguson Marsh Jr. Ziegler was confirmed by the United States Senate on May 1, 1978, and received his commission the following day. He served as Chief Judge from 1994 to 2001. He assumed senior status on October 1, 2001, serving in that capacity until his retirement from the bench on May 31, 2003. Ziegler served as a member of the Judicial Conference of the United States for three years, and the Judicial Council of the Third Circuit for seven years. Along with being an outstanding Judge, Judge Ziegler was a great, kind, considerate and thoughtful mentor and professor to law students and new lawyers. He took his profession and position seriously but was compassionate to the human condition.