| Year | Title | Role | Notes |
| 1985 | Polka Dot Door | Host | |
| 1990–1991 | The Flash | Sabrina | 5 episodes |
| 1995 | Homicide: Life on the Street | Det. Theresa Walker | 3 episodes |
| 1995–1999, 2008 | ER | Jeanie Boulet | Series regular; 102 episodesWon: Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series (1996, 1997, 1998, 1999)Viewers for Quality Television for Best Supporting Actress in a Drama Series (1997, 1998)Nominated: Golden Globe Award for Best Supporting Actress – Series, Miniseries or Television Film (1998)Primetime Emmy Award for Outstanding Supporting Actress in a Drama Series (1997, 1998)Screen Actors Guild Award for Outstanding Performance by an Ensemble in a Drama Series (2000)NAACP Image Award for Outstanding Actress in a Drama Series (1996, 1997, 1998, 1999) |
| 2001–2002 | The Agency | Lisa Fabrizzi | Regular: episodes 1–13, 21–22 |
| 2002, 2007–2011 | Law & Order: Special Victims Unit | Violet Tremain (2002) / Christine Danielson (2007–2011) | 4 episodes |
| 2002 | Little John | Natalie Britain | TV film; Nominated – NAACP Image Award for Outstanding Actress in a Television Film |
| 2003–2004 | 1-800-Missing | Brooke Haslett | Series regular; season 1: 18 episodes |
| 2005 | Numb3rs | Erica Quimby | Episode: "Noisy Edge" |
| 2008–2009 | Raising the Bar | Rosalind Whitman | Series regular; 25 episodes |
| 2010 | Drop Dead Diva | Professor Kathy Miller | Episode: "Freeze the Day" |
| 2011 | Jesse Stone: Innocents Lost | Thelma Gleffey | TV movie |
| 2012 | Jesse Stone: Benefit of the Doubt | Thelma Gleffey | TV movie |
| 2013 | Betty & Coretta | Myrlie Evers-Williams | Television film |
| 2013 | Falling Skies | Marina Peralta | 10 episodes |
| 2014 | Happy Face Killer | FBI Agent Melinda Gand | TV movie |
| 2015 | The Music in Me | Gloria | TV movie |
| 2015–2017 | The Blacklist | Dr. Selma Orchard | 2 episodes |
| 2015–2019 | Mr. Robot | Dr. Krista Gordon | Recurring role |
| 2015 | Jesse Stone: Lost in Paradise | Thelma Gleffey | TV movie |
| 2016–2017 | Saints & Sinners | Mayor Pamela Clayborne | Series regular |
| 2017 | The Breaks | Mattie Taylor | 4 episodes |
| 2017 | The Librarians | Jade Wells | Episode: "And the Silver Screen" |
| 2018 | Blindspot | Kira Evans | 6 episodes |
| 2018–2019 | Cloak & Dagger | Adina Johnson | Series regular |
| 2019–2021 | City on a Hill | Eloise Hastings | Recurring role |
| 2021 | Blue Bloods | ATF Agent Rachel Weber | 2 episodes |
| 2022 | The First Lady | Valerie Jarrett | 3 episodes |
| 2022–2023 | The Equalizer | Trish | 2 episodes |
| 2023 | NCIS: Hawaiʻi | Col. Tannon McCarthy | Episode: "Cabin Fever" |
| 2024 | Elsbeth | Claudia Payne | Recurring role |
| 2025 | The Better Sister | Michelle Sanders | Recurring role |
| 2025 | Boston Blue | Mae Silver | Series regular |
