| The 24th Annual A Home for the Holidays at the Grove TV Special | 2022 | Writer | Writer |
| The Tiger Rising | 2022 | Actress | Caroline Horton |
| Country Comfort | 2021 | Actress | Bailey |
| Bayou Caviar | 2018 | Actress | Shelly |
| Scorpion | 2014–2018 | Actress | Paige Dineen |
| The Lost Wife of Robert Durst | 2017 | Actress | Kathie |
| Katharine McPhee: Lick My Lips Music Video | 2015 | Actress | Katharine McPhee |
| It Could Be Worse | 2014 | Actress | Lucy |
| In My Dreams | 2014 | Actress | Natalie Russo |
| Smash | 2012–2013 | Actress | Karen Cartwright |
| Family Guy | 2012 | Actress | Mother Maggie (voice) |
| Peace, Love & Misunderstanding | 2011 | Actress | Sara |
| Shark Night | 2011 | Actress | Beth |
| You May Not Kiss the Bride | 2011 | Actress | Masha Nikitin |
| The Pink House | 2010 | Actress | Emily |
| Community | 2010 | Actress | Amber |
| Tit for Tat | 2009 | Actress | Kat |
| CSI: NY | 2009 | Actress | Odessa Shaw |
| The House Bunny | 2008 | Actress | Harmony |
| Crazy | 2008 | Actress | Paramount Girl |
| Katharine McPhee: Love Story | 2007 | Actress | Katharine McPhee |
| Ugly Betty | 2007 | Actress | Katharine McPhee |
| Lonelygirl15 | 2007 | Actress | Random Girl |
| Live with Kelly and Mark | 2022–2023 | Soundtrack | performer: "My Grown-Up Christmas List" |
| Good Morning America | 2023 | Soundtrack | performer: "Rudolph the Red-Nosed Reindeer" |
| Silent Night: A Song for the World | 2020 | Soundtrack | performer: "Silent Night" |
| Bombshell in Concert | 2020 | Soundtrack | performer: "Let Me Be Your Star", "The 20th Century Fox Mambo", "Never Give All The Heart", "Public Relations", "Don't Forget Me", "Big Finish" |
| Book Club | 2018 | Soundtrack | performer: "Living in the Moment" |
| Stayin' Alive: A Grammy Salute to the Music of the Bee Gees | 2017 | Soundtrack | performer: "Emotion" |
| Scorpion | 2014 | Soundtrack | performer: "Can't Take My Eyes Off Of You" (uncredited) |
| Smash | 2012–2013 | Soundtrack | performer: "Rewrite This Story" |
| I Don't Know How She Does It | 2011 | Soundtrack | performer: "Love Story" |
| Peace, Love & Misunderstanding | 2011 | Soundtrack | performer: "Seems Like Yesterday" |
| Shark Night | 2011 | Soundtrack | performer: "Shark Bite" |
| You May Not Kiss the Bride | 2011 | Soundtrack | writer: "Beautiful Stranger" |
| The Tonight Show with Jay Leno | 2010 | Soundtrack | performer: "Jingle Bells" |
| I Am | 2010 | Soundtrack | performer: "Say Goodbye" |
| The Tonight Show with Conan O'Brien | 2010 | Soundtrack | performer: "Had It All" (uncredited) |
| The House Bunny | 2008 | Soundtrack | performer: "I Know What Boys Like" |
| Cover Art TV Series | 2007 | Soundtrack | performer: "Me" |
| American Idol | 2006 | Soundtrack | performer: "Black Horse and the Cherry Tree", "Somewhere Over the Rainbow", "My Destiny" |
| Celebrity Wheel of Fortune | 2025 | Self | Self - Celebrity Contestant |
| 58th Annual CMA Awards | 2024 | Self | Self - Presenter |
| Andrea Bocelli 30: The Celebration | 2024 | Self | Self |
| Celebrity Family Feud | 2024 | Self | Self - Contestant |
| Entertainment Tonight | 2006–2024 | Self | Self |
| Jesse Watters Primetime | 2024 | Self | Self - At Golden Globes |
| Live with Kelly and Mark | 2006–2023 | Self | Self - Musical Guest |
| Good Morning America | 2023 | Self | Self - Musical Guest |
| Christmas in Rockefeller Center | 2011–2023 | Self | Self |
| The 97th Annual Macy's Thanksgiving Day Parade | 2023 | Self | Self |
| Dr. Phil | 2022–2023 | Self | Self |
| The Talk | 2014–2023 | Self | Self |
| The Jennifer Hudson Show | 2023 | Self | Self (as Katharine McPhee Foster) |
| The 24th Annual A Home for the Holidays at the Grove TV Special | 2022 | Self | Self |
| The Wonderful World of Disney: Magical Holiday Celebration | 2022 | Self | Self - Performer |
| CBS Mornings | 2022 | Self | Self |
| Sherri | 2022 | Self | Self |
| The Morning Show | 2022 | Self | Self (Live in Studio) (as Katherine McPhee Foster) |
| Today | 2019–2022 | Self | Self - Guest |
| The Masked Singer | 2021 | Self | Self - Banana Split |
| Dish Nation | 2021 | Self | Self |
| Nick Cannon | 2021 | Self | Self |
| Daily Blast Live | 2021 | Self | Self |
| Home & Family | 2021 | Self | Self |
| Broadway Profiles with Tamsen Fadal | 2020–2021 | Self | Self |
| The Kelly Clarkson Show | 2021 | Self | Self - Musical Guest (as Katharine McPhee Foster) |
| American Idol | 2006–2021 | Self | Self - Duo Partner Alyssa Wray |
| Made in Hollywood | 2021 | Self | Self |
| Celebrity Page | 2019–2021 | Self | Self |
| Informed Pregnancy Podcast | 2021 | Self | Self |
| I Can See Your Voice | 2020 | Self | Self - Guest Panelist & Performer |
| Silent Night: A Song for the World | 2020 | Self | Self |
| Bombshell in Concert | 2020 | Self | Self |
| Broadway.com #LiveatFive | 2020 | Self | Self |
| Stars in the House | 2020 | Self | Self |
| On Stage TV Series | 2020 | Self | Self |
| The Rosie O'Donnell Show: A Benefit for the Actors Fund | 2020 | Self | Self |
| The X Factor: Celebrity | 2019 | Self | Self |
| David Foster: Off the Record | 2019 | Self | Self |
| Vocal Star Music Awards TV Special | 2019 | Self | Self |
| The Sara Cox Show | 2019 | Self | Self - Guest |
| Good Morning Britain | 2019 | Self | Self - Actress |
| Unqualified | 2019 | Self | Self - Guest |
| Sunday Brunch | 2019 | Self | Self - Guest |
| The Kick Ash Bash Concert Film | 2018 | Self | Self |
| The 72nd Annual Tony Awards | 2018 | Self | Self - Presenter |
| Zoltan Maga: Live from Budapest with David Foster TV Special | 2018 | Self | |
| Show People with Paul Wontorek | 2018 | Self | Self |
| The Chew | 2018 | Self | Self - Guest |
| Soundstage | 2018 | Self | Self |
| MVP: Most Valuable Performer | 2018 | Self | Self |
| Harry | 2017 | Self | Self - Musical Guest |
| Stayin' Alive: A Grammy Salute to the Music of the Bee Gees | 2017 | Self | Self - Performer |
| E! Live from the Red Carpet | 2015–2017 | Self | Self |
| Rock the Troops | 2016 | Self | Self |
| 2016 Hero Dog Awards TV Special | 2016 | Self | Self |
| 2016 Primetime Creative Arts Emmy Awards | 2016 | Self | Self - Performer |
| National Memorial Day Concert TV Series | 2009–2016 | Self | Self - Performer |
| The Late Show with Stephen Colbert | 2016 | Self | Self - Guest |
| Lip Sync Battle | 2016 | Self | Self - Competitor |
| Sinatra 100: An All-Star Grammy Concert | 2015 | Self | Self - Performer |
| 2015 Primetime Creative Arts Emmy Awards | 2015 | Self | Self - Presenter |
| Hollywood Game Night | 2015 | Self | Self - Celebrity Player |
| The Late Late Show with James Corden | 2015 | Self | Self - Guest |
| Comedy Central Roasts | 2015 | Self | Self - Audience Member |
| Fashion Police | 2015 | Self | Self - Special Guest |
| The 57th Annual Grammy Awards | 2015 | Self | Self - Presenter |
| Super Bowl's Greatest Commercials 2015 TV Special | 2015 | Self | Self |
| The 41st Annual People's Choice Awards | 2015 | Self | Self |
| BELLOmag Presents: A Conversation with Katharine McPhee TV Special | 2015 | Self | Self - Guest |
| Quiet on the Set | 2014–2024 | Self | Self |
| The 16th Annual 'A Home for the Holidays' TV Special | 2014 | Self | |
| Conan | 2014 | Self | Self - Guest |
| The Insider | 2014 | Self | Self - Scorpion |
| CBS Mornings | 2014 | Self | Self - Guest |
| Late Show with David Letterman | 2014 | Self | Self - Guest |
| Extra | 2014 | Self | Self |
| Fashion News Live | 2005–2013 | Self | Self |
| 2013 Primetime Creative Arts Emmy Awards | 2013 | Self | Self - Presenter |
| Rachael Ray | 2007–2013 | Self | Self - Guest |
| Late Night with Jimmy Fallon | 2012–2013 | Self | Self - Guest |
| 9th Annual Style Awards TV Special | 2012 | Self | Self |
| The Tonight Show with Jay Leno | 2006–2012 | Self | Self - Guest |
| The Ellen DeGeneres Show | 2007–2012 | Self | Self - Guest |
| National Football League Honors TV Special | 2012 | Self | Self |
| The 69th Annual Golden Globe Awards | 2012 | Self | Self - Presenter |
| The Voice | 2011 | Self | Self - Performer |
| All American New Year 2011 | 2010 | Self | Self - Musical Guest |
| When I Was 17 | 2010 | Self | Self |
| Us Weekly: YouTube Channel TV Series | 2010 | Self | Self |
| The Soup | 2010 | Self | Self |
| The Wendy Williams Show | 2010 | Self | Self - Guest |
| The Bonnie Hunt Show | 2010 | Self | Self - Guest |
| Chelsea Lately | 2010 | Self | Self - Guest |
| An Evening of Stars: Tribute to Lionel Richie | 2010 | Self | Self |
| The Biggest Loser | 2010 | Self | Self |
| Jimmy Kimmel Live! | 2007–2010 | Self | Self - Musical Guest |
| The Tonight Show with Conan O'Brien | 2010 | Self | Self - Musical Guest |
| Chris Botti in Boston | 2009 | Self | Self |
| Macy's Thanksgiving Day Parade | 2009 | Self | Self |
| Kaleidoscope TV Special | 2009 | Self | Self |
| Great Performances | 2008 | Self | Self |
| The View | 2008 | Self | Self - Guest |
| Karaoke Revolution Presents: American Idol Encore 2 | 2008 | Self | Self (uncredited) |
| Kira Plastinina: In Her Own Words TV Special | 2008 | Self | Self |
| The Teen Choice Awards 2008 | 2008 | Self | Self - Presenter |
| Macy's 4th of July Fireworks Spectacular TV Special | 2008 | Self | Self |
| 2008 MTV Movie Awards | 2008 | Self | Self - Presenter |
| The Red Dress Collection 2007 Fashion Show | 2008 | Self | Self |
| Karaoke Revolution Presents: American Idol Encore | 2008 | Self | Self (uncredited) |
| 2008 FedEx Orange Bowl TV Special | 2008 | Self | Self - National Anthem Singer |
| Walt Disney World Christmas Day Parade | 2007 | Self | Self |
| Mother Goose Parade | 2007 | Self | Self - Performer |
| Access Hollywood | 2007 | Self | Self |
| The Morning Show with Mike & Juliet | 2007 | Self | Self - Guest |
| CBS Mornings | 2007 | Self | Self |
| Cover Art TV Series | 2007 | Self | Self |
| Larry King Live | 2006–2007 | Self | Self - Guest |
| Karaoke Revolution Presents: American Idol | 2007 | Self | Self (uncredited) |
| AOL Sessions | 2006 | Self | Self - Performer |
| The 8th Annual 'A Home for the Holidays' TV Special | 2006 | Self | |
| The 2006 Billboard Music Awards | 2006 | Self | Self |
| VH1 Big in 06 Awards | 2006 | Self | Self |
| Christmas Celebration at the Grove TV Movie | 2006 | Self | Self |
| 2006 American Music Awards | 2006 | Self | Self - Presenter |
| THS Investigates | 2006 | Self | Self |
| The Dr. Keith Ablow Show | 2006 | Self | Self - Guest |
| JCPenney Jam: The Concert for America's Kids | 2006 | Self | Self - Performer |
| American Idol Extra | 2006 | Self | Self |
| CBS News Sunday Morning with Jane Pauley | 2025 | Archive Footage | Karen Cartwright (archive footage) |
| Entertainment Tonight | 2015–2024 | Archive Footage | Self (archive footage) |
| Dish Nation | 2022 | Archive Footage | Self (archive footage) |
| Inside Edition | 2021 | Archive Footage | Self (archive footage) |
| The Hollywood Moment at Home Edition | 2020 | Archive Footage | Self (archive footage) |
| Vocal Star - New Years Special! TV Special | 2019 | Archive Footage | Self (archive footage) |
| Entertainment Tonight Canada | 2018 | Archive Footage | Self (archive footage) |
| Extra | 2017 | Archive Footage | Self (archive footage) |
| Clive Davis: The Soundtrack of Our Lives | 2017 | Archive Footage | Self (archive footage, uncredited) |
| The Insider | 2014 | Archive Footage | Self - Scorpion (archive footage) |