From Bulbapedia, the community-driven Pokémon encyclopedia.
The Pokémon franchise first reached Australia in late 1998 with the release of Pokémon Red and Blue and the airing of the anime.
Pokémon video games
All Pokémon games that have been released in the United States have also been released in Australia, except Hey You, Pikachu!. The Australian release dates tend to be some time after the American release dates, but before the European release dates. However, there are times where Australian release dates are before the American release dates such as Pokémon Gold and Silver, Pokémon Trading Card Game, and PokéPark Wii: Pikachu's Adventure. There are also times where Australian release dates are after the European release dates such as Pokémon Ranger: Guardian Signs, Pokémon Rumble Blast, and Pokémon Black and White.
Games that are released in Australia are inconsistent with Australian English spelling. For example, spelling variations such as color and center are not changed to colour and centre for the Australian releases.
Event Pokémon in Australia
Event Pokémon have been released in Australia sporadically. Majority of the events since 1999 were organised by Nintendo Australia including the Pokémon Mew Tour in 1999 and Pokémon Celebi Tour in 2001 which happened to be the last event to receive any event Pokémon in Australia. From 2002-2006, Australians have not received any event Pokémon, including Pokémon from the Generation III era, meaning players who had Pokémon Ruby and Sapphire, Pokémon FireRed and LeafGreen, or Pokémon Emerald were not able to obtain all the Pokémon in these games.
From 2007, the recent introduction of Wi-Fi events has allowed Australian players access to many previously unavailable event Pokémon. However, despite Australia being one of the major countries involved with Pokémon, Australians did not get the chance to obtain certain event Pokémon including the event Regigigas that would allow players to obtain Regirock, Regice, and Registeel in Pokémon Platinum for those who don't own any of the Game Boy Advance Pokémon games, and the event Celebi that would allow players to battle Giovanni and obtain Zorua in Pokémon Black and White.
Network Ten is a TV channel which used to air the Pokémon anime in Australia. It originally aired Pokémon episodes during its programming block called Cheez TV before its successor, Toasted TV. For a short time during the peak of Pokémon's popularity in Australia, some anime episodes, such as the first episode, were aired on Channel Ten as re-runs during prime-time slots in the late afternoon/night time. However, on Monday, 27 February 2012, Toasted TV was moved to Channel Ten's sister channel, Eleven, where it currently remains.
Toasted TV is an Australian programming block broadcast on the free-to-air station Eleven (prior to February 27, 2012, Network Ten). It screens every day of the week from 6:00 a.m. to 9:00 a.m.
Launched on August 22, 2005, Toasted TV has aired the Pokémon anime to Australian audiences since April 26, 2006.
Toasted TV was launched to replace Cheez TV, which had a similar scope. It shows cartoons and pre-recorded entertainment segments targeted at children. Its current hosts are Seamus Evans and Kellyn Morris. Former hosts include Sean Kennedy, Dan Sweetman, Pip Russell.
Starting from February 10 2012, Toasted TV is currently airing Pokémon Black & White: Rival Destinies at 8 am every Sundays and Mondays.
It has also previously aired Pokémon: Advanced Battle, Pokémon: Battle Frontier, Pokémon: Diamond and Pearl, Pokémon Diamond & Pearl: Battle Dimension, Pokémon Diamond & Pearl: Galactic Battles, Pokémon Diamond & Pearl: Sinnoh League Victors, and Pokémon: Black & White. This includes all Pokémon Mystery Dungeon: Team Go-Getters Out of the Gate!, Pokémon Mystery Dungeon: Explorers of Time & Darkness, Pokémon Mystery Dungeon: Explorers of Sky - Beyond Time & Darkness, and The Mastermind of Mirage Pokémon.
Along with showing the anime series, Toasted TV also aired the Australian FreeTV debut of The Rise of Darkrai on April 23, 2012. Since then, Toasted TV continued to show the FreeTV debut of the following movies up to White—Victini and Zekrom / Black—Victini and Reshiram.
Due to the popularity of Pokémon by viewers, Toasted TV has run several events such as many Pokémon focused competitions, apart from the usual showing of the anime series.
Notably, for the release of Pokémon Black and White, Toasted TV ran a promotion in which the winner received a Nintendo DSi and either Pokémon Black or White, with four runners-up receiving either Pokémon Black or White. The competition closed on April 1, 23:59 Australian Eastern Standard Time (UTC+10:00). They have since run more Pokémon-based competitions including one which ended on February 24, 2013 23:59 in which the winner received a Pokémon Black & White: Rival Destinies Season 15 DVD collection, Kyurem VS. The Sword of Justice movie DVD, PokéPark Wii: Pikachu's Adventure Wii game as well as a Pokémon plush toy. Toasted TV is also currently running a competition where a winner would win Season's 1 through to 12 on DVD. The competition ends March 31, 2013, 23:59.
Other notable events include:
On February 27, 2012, Toasted TV switched from Network Ten to its sister channel Eleven. During this switch, Pokémon: Black & White changed from airing once per week to every day of the week, except for Saturdays.
Toasted TV was originally filmed at Warner Bros. Movie World, then moved to Sea World in 2007. Prior to moving to Dream World, episodes were occasionally filmed at Wet'n'Wild Water World and at the Australian Outback Spectacular. After the 2011 road trip, Toasted TV was filmed at Dreamworld. In July 2012, Toasted TV moved to a studio rather than being filmed at a theme park.
Mewtwo Strikes Back, The Power of One and Spell of the Unown were screened in theatres, while Celebi: Voice of the Forest and Pokémon Heroes were released straight to video. Jirachi: Wish Maker and Destiny Deoxys have not been released in Australia. Lucario and the Mystery of Mew, Pokémon Ranger and the Temple of the Sea, The Rise of Darkrai, Giratina and the Sky Warrior, Arceus and the Jewel of Life and Zoroark: Master of Illusions have all been released on DVD. White—Victini and Zekrom/Black—Victini and Reshiram was released on DVD March 21, 2012, following a two-day limited release of White—Victini and Zekrom in theaters in February. With thanks to Hoyts, Bulbagarden was able to provide 10 free double passes to this screening.
Pokémon manga translated into English by Chuang Yi is distributed in Australia through Madman Entertainment.
Pokémon Trading Card Game
The Pokémon Trading Card Game was very popular when it was first released in Australia. However, some of the schools banned this card game (along with other card games) as it deemed to be a "classroom distraction". Despite this setback, the card game is still being sold in Australia.
Unlike the Video Game Championships, Australia has always taken part in the World Championships. In 2011, Christopher Kan became the first Australian player to become the world champion in the senior division. 
In September and October 2006, Nintendo Australia hosted the Pokémon 10th Anniversary - Journey Across Oz Tour (similar to the Journey Across America tour in the United States).
In 2007, Nintendo Australia hosted the Pokémon Diamond and Pearl Connection Tour to celebrate the release of Pokémon Diamond and Pearl. During the tour, Nintendo DS users who owned Pokémon Diamond and Pearl got the chance to participate in the tournaments for a chance to win prizes, including a limited edition Nintendo DS Lite which had the "Nintendo DS Connection Tour '07 Champion" engraving for the winners at each tournament. The very first event was held on June 30, 2007, exactly nine days since the release of the games in Australia. 
On March 29, 2011, Nintendo Australia announced that more than 77,000 copies of Pokémon Black and White game were sold on its first week of release. As a result, this was the biggest selling first week release of any Nintendo game in Australia. Pokémon HeartGold and SoulSilver made over 45,000 sales in its first week. 
In April and May 2011, after a month from the release of Pokémon Black and White, Nintendo Australia held the Pokémon Black Version and Pokémon White Version Battle Competition tournaments at Sydney, Melbourne, Adelaide, Brisbane and Perth. The winner at each location won a Nintendo 3DS. 
Pokémon World Championship
In 2000, Sydney hosted the first ever Pokémon World Championship. It was held at the Sydney University in Sydney, Australia where players from Australia, Belgium, France, Germany, the Netherlands, Spain, the United Kingdom and the United States competed using Pokémon Red and Blue and Pokémon Yellow. At the same time, Pokémon Park was opened for the general public where they had the chance to play Pokémon Gold and Silver for the first time, watch the latest Pokémon episodes and see live performances.
Since 2009, despite the World Championships having the Video Game Championships, Australia has not been represented. The reason for this is unknown, but with the recent success of an Australian player winning the World Championships in the Trading Card Game and the success of the Pokémon video games in Australia, it probably won't be long for Australia to have representatives playing in the Video Game Championships.