In American television during 2003, notable events included television series debuts, finales, cancellations, and new channel initiations. NCIS (originally referred to as Navy NCIS), a spin-off of JAG, premiered on September 23, 2003 on CBS, becoming the third-longest-running scripted, nonanimated U.S. prime-time TV series currently airing, and has later spawned multiple spin-offs and was voted America's favorite television series in 2011. Other notable shows that premiered that year included Arrested Development, Jimmy Kimmel Live!, Two and a Half Men, The Venture Bros., One Tree Hill, The O.C., Nip/Tuck, and Teen Titans. Later 2010s/2020s TV shows like Better Call Saul (2015-2022) and the television adaptation of The Last of Us (2023–present) are set in 2003.

Events

January

February

March

April

May

June

July

August

September

October

November

December

Programs

Debuts

Returning this year

Ending this year

Entering syndication this year

Changes of network affiliation

Made-for-TV movies

Networks and services

Launches

Conversions and rebrandings

Closures

Television stations

Station launches

Network affiliation changes

Station closures

Births

Deaths

Television debuts