| William H. Macy | |
 | |
| Personal details | |
| Date of birth | March 13, 1950 |
| Birth place | Miami, Florida, USA |
| Years active | 1978 to present |
| ER | |
| Character | David Morgenstern |
| Seasons | 1, 2, 3, 4, & 15 |
| First episode | "24 Hours" |
| Last episode | "A Long, Strange Trip" |
| Credits | 31 episodes (see below) |
William H. Macy, born March 13, 1950 in Miami, Florida, USA, is an actor. He special guest starred as Doctor David Morgenstern from the first season to the fourth season. He debuted in the series pilot "24 Hours". He reprised the role for an appearance in the fifteenth and final season. He appeared in 31 episodes over the course of the series. He has been active since 1978. He has gone on to star in the drama Shameless, reuniting him with ER Executive Producer John Wells. He is also famous for his film acting career. He starred in the films Fargo (1996), Pleasantville (1998), Magnolia (1999), Jurassic Park III (2001), and The Cooler (2003).
He is married to fellow actor Felicity Huffman. He guest starred opposite her in the situation comedy Sports Night.