Television
From 1999 to 2006, O'Donnell was associated with the television drama The West Wing, writing 16 episodes and serving as executive story editor for 12 episodes (1999–2000), as co-producer for five episodes (2000), as producer for 17 episodes (2000–2001), as consulting producer for 44 episodes (2003–2005), and as executive producer for 22 episodes (2005–2006). He won the 2001 Primetime Emmy Award for Outstanding Drama Series for The West Wing and was nominated for the 2006 Emmy in the same category.
In 2002, O'Donnell was supervising producer and writer for the television drama First Monday; and in 2003 he was creator, executive producer, and writer for the television drama Mister Sterling.
In 2009, O'Donnell became a regular contributor on Morning Joe with Joe Scarborough. His aggressive debate style on that program and others led to several on-air confrontations, including an interview with conservative Marc Thiessen on Morning Joe that became so heated that Scarborough took O'Donnell off the air. Also in 2009 and 2010, O'Donnell began appearing frequently as a substitute host of Countdown with Keith Olbermann, particularly when Olbermann's father was ill in the hospital.
On September 27, 2010, O'Donnell began hosting a 10 p.m. show on MSNBC, called The Last Word with Lawrence O'Donnell. On January 21, 2011, it was announced that O'Donnell would take over the 8 p.m. slot from Keith Olbermann after Olbermann announced the abrupt termination of his show, Countdown with Keith Olbermann. Beginning October 24, 2011, The Last Word with Lawrence O'Donnell switched time slots with The Ed Show, with Ed Schultz taking over the 8 p.m. Eastern slot, and O'Donnell returning to the 10 p.m. Eastern slot.
On September 20, 2017, an eight-minute video clip was leaked; it showed O'Donnell angrily cursing and swearing about background noise between segments of a live broadcast that had aired on August 29, 2017. O'Donnell apologized on Twitter, and the leaker was subsequently fired.
O'Donnell gave an impassioned opening on his show on July 7 and 8, 2026, about the controversies surrounding the Maine Democratic U.S. Senate nominee, Graham Platner. He said he never interviewed the candidate, noting he was suspicious of his background. He went on to say that, despite his image as a "working man," he came from a wealthy family and that his image was largely crafted by outsiders. The dialogue stood out because the network had been one of those that helped elevate the Platner candidacy. “We've been very careful about what campaigns we have focused on here,” O’Donnell said.
O'Donnell played Lee Hatcher, the Henrickson family attorney, in the HBO series Big Love, about a polygamous family in Utah. In addition to being a producer on The West Wing, O'Donnell also played President Josiah Bartlet's father in a flashback sequence of the episode "Two Cathedrals". O'Donnell portrayed Judge Lawrence Barr in two episodes of Monk and played himself on an episode of Showtime's Homeland.
