| Year | Title | Role | Notes |
| 1998 | Movie Surfers | Himself | Episode: "Mulan" |
| 1999 | As the World Turns | Himself | Episode: "May 21, 1999" & "May 24, 1999" |
| 1999–06 | Making the Video | Himself | Recurring guest |
| 2000–01 | Hollywood Squares | Himself/Panelist | Recurring panelist |
| 2000–04 | Mad TV | Himself | Guest (seasons 5 & 10) |
| 2000–07 | Christmas in Rockefeller Center | Himself | Recurring guest |
| 2001 | Who Wants to Be a Millionaire? | Himself/Contestant | Episode: "Top of the Charts Edition, Show 1 & 3-4" |
| 2003 | Room Raiders | Himself/Host | Episode: "Homecoming with Nick and Jessica" |
| Punk'd | Himself | Episode: "Episode 1.6" |
| 2003–05 | Newlyweds: Nick and Jessica | Himself | Main cast |
| 2004 | Saturday Night Live | Himself/Host | Episode: "Jessica Simpson and Nick Lachey/G-Unit" |
| The Apprentice | Himself | Episode: "Down to the Wire: Part 2" |
| The Ashlee Simpson Show | Himself | Recurring cast (season 1) |
| VH1 Big in '04 Awards | Himself | Host |
| 10 Things Every Guy Should Experience | Himself | Episode: "Kentucky Derby" |
| American Dreams | Tom Jones | Episode: "To Tell the Truth" |
| I'm with Her | Tyler Vance | Episode: "I'm Not With Her" |
| Charmed | Leslie St. Claire | Recurring role (season 7) |
| Hope & Faith | Chris | Episode: "Just-In Time" |
| 2005 | E! True Hollywood Story | Himself | Episode: "Jessica, Ashlee and the Simpson Family" |
| B InTune TV | Himself | Episode: "Episode 1.4" |
| 2006 | VH1 News Presents | Himself | Episode: "Celebrity Pre-nups" |
| Behind the Music | Himself | Episode: "Nick Lachey" |
| VH1: All Access | Himself | Episode: "Celeb Breakups & Scandals" |
| It Takes Two | Himself | Episode: "Series 1 Grand Final" |
| Saturday Disney | Himself | Episode: "In the House with Nick Lachey" |
| Born to Be... | Himself | Episode: "Nick Lachey" |
| Overhaulin' | Himself | Episode: "Pop Star Steal" |
| Twins | Charlie | Episode: "Himbo" |
| 2007 | Punk'd | Himself | Episode: "Episode 8.8" |
| Clash of the Choirs | Himself | Main cast |
| 2008 | High School Musical: Get in the Picture | Himself | Host |
| The Girls Next Door | Himself | Episode: "Kentucky Fried" |
| 2009 | One Tree Hill | Himself | Recurring role (season 6) |
| Are You Smarter than a 5th Grader? | Himself/Contestant | Episode: "November 10, 2009" |
| Super Dave's Spike Tacular | Himself | Episode: "Paint Ball Battle of the Decade" |
| 2009–14 | The Sing-Off | Himself | Host |
| 2010 | The Soup | Himself | Episode: "Episode 7.10" |
| The Late Late Show with Craig Ferguson | Ronnie | Episode: "Episode 6.85" |
| 2011 | Macy's 4th of July Fireworks Spectacular | Host | Host |
| Hawaii Five-0 | Tyler | Episode: "Powa Maka Moana (Pirate)" |
| 2012 | Stars Earn Stripes | Himself/Contestant | Main cast |
| 2012–16 | Live with Kelly and Mark | Himself | Guest co-host |
| 2013 | The Price Is Right | Himself/Contestant | Episode: "February 18, 2013" |
| The Winner Is | Himself | Host |
| 2014–15 | Big Morning Buzz Live | Himself | Recurring host (seasons 9–11) |
| 2015 | Lachey's: Raising the Bar | Himself | Co-host |
| FABLife | Himself/Guest Co-Host | Episode: "Episode 1.50" |
| 2016 | Burgers, Brew & 'Que | Himself | Episode: "Phenomenal Philly Food Feast" |
