1 February – Deal or No Deal debuts its 5.30pm timeslot on Seven which would last until 2015. This proves to be a massive ratings hit leading into Seven's 6pm news bulletin. Its success proves too much for the Nine Network, with reworked game shows including The Price is Right, Bert's Family Feud and Million Dollar Wheel of Fortune all failing in the dreaded 5:30pm timeslot until Hot Seat's arrival in 2009.
2 February – Top-rating game show Wheel of Fortune makes a rebranding and a super new-look over to continue its long-run. Also, Steve Oemecke takes over from Rob Elliott as the show's final original main host.
February – Nine launches a new afternoon news service to compete against Seven's 4:30 pm news, which was launched the previous year to provide viewers with up-to-date information on the War on Iraq.
14 March – Foxtel launches its new digital service, Foxtel Digital.
21 April - A live episode of Blue Heelers goes to air on the Seven Network, titled "Reasonable Doubt". Although this particular episode earned reasonable ratings, peaking with 693,000 viewers in Melbourne, the rest of the season is a failure ratings-wise.
1 May – Network Ten breaks with years of tradition and abandons the Sunday night movie after poor ratings. Instead, it screens episodes of '. Most other networks follow suit later on.
2 May – American police procedural television series NCIS created by Donald P. Bellisario the creator of JAG debuts on Network Ten.
9 May – American legal drama series JAG switches over to airing on Network Ten as part of an NCIS episode called "Hung Out to Dry" with the appearance of Lieutenant Bud Roberts after Ten acquired the rights to CBS from the Seven Network. However, the series will air on Seven one last time in October.
17 June, 5:58pm – Dean Cartechini becomes the first person to win Deal or No Deals top prize, winning $200,000.
26 July – Broken Hill resident Trevor Butler proposes to his girlfriend immediately after winning A$1,000,000 on Big Brother.
24 August – After a short-lived return at its new 11:30 am timeslot, Ten axes vintage Neighbours episodes again after more very bad ratings. The following Monday, Ten extends its morning news into a one-hour format.
30 August – Immediately after the closing ceremony of the Athens Olympics, the first ever Sunrise is broadcast from the Seven Network's new Martin Place studios. On the same night, Seven News relaunches nationwide with a complete overhaul of graphics, a new musical theme and a new set in Sydney. Nine News counters by introducing live CBD backdrops on its Sydney and Brisbane bulletins.
12 September - The 2001 war film Behind Enemy Lines starring Owen Wilson and Gene Hackman premieres on the Seven Network.
4 October – British long running children's animated series Peppa Pig debuts on ABC.
5 October – After a five-year absence, Daryl Somers returns to television to host a brand new series on Seven Network called Dancing with the Stars based on the American light entertainment reality series of the same name.
21 November – 16-year-old Casey Donovan wins the second series of Australian Idol defeating 21-year-old favourite, Anthony Callea. Her debut single "Listen with Your Heart" reaches number one in the ARIA Charts in December 2004.
23 November – Home and Away actress Bec Cartwright and her partner Michael Miziner are crowned season champions as the first season of Dancing with the Stars reaches its grand final.
11 December – The Network Ten is the next Australian television network to introduce a watermark on its programs, although the watermark is now broadcast on Ten News. It was located on the bottom left of the screens before switching to bottom right in 2006.
18 December – American science fiction fantasy series Smallville airs on the Nine Network for the very last time before changing broadcasts to Network Ten which won't happen until sometime next year.
23 December – American animated science fiction sitcom Futurama created by Matt Groening the creator of The Simpsons airs on the Seven Network for the very last time before changing broadcasts to Network Ten which won't happen until the end of next year.
December – Seven, Nine & TEN withdrawn their opening to movies - movie openers are replaced by classification boards instead.
Wheel of Fortune's attempt for a major revamp backfires and is quietly cancelled due to low ratings - leaving Deal or No Deal'' the absolute only game show remaining, leading into Seven's 6pm news bulletin.
December – The Nine Network claims the ratings season for the fourth consecutive year, winning 38 out of 40 weeks, while Network Ten finishes ahead of the Seven Network nationally for the first time.
This is a list of programs which made their premiere on an Australian television network that had previously premiered on another Australian television network. The networks involved in the switch of allegiances are predominantly both free-to-air networks or both subscription television networks. Programs that have their free-to-air/subscription television premiere, after previously premiering on the opposite platform are not included. In some cases, programs may still air on the original television network. This occurs predominantly with programs shared between subscription television networks.
International
Subscription premieres
This is a list of programs which made their premiere on Australian subscription television that had previously premiered on Australian free-to-air television. Programs may still air on the original free-to-air television network.
