You have to import it from pokemon Platinum,diamond, soulsilver ect, or you have to trade for it.
There was an event, but it is over. You can get it from Wi-Fi.
Celebi isn't available in Pokemon Black and White. You have to transfer it into Pokemon Black and White or trade for one.
You can not collect a celebi on black or white. You need to transfer from the 4th generation.
You cannot find Celebi in-game in Pokemon Black and White. You must get it from the Pokemon Black and White Tour.
There is no in game Celebi, you need to transfer one from another game.
celebi.
Zorua
i need a celebi on pokemon white how to get it
You can't catch celebi in pokemon white.
You cannot. Once in Black/White it cannot be sent back
you have to trade celebi to your black or white game (P.S. it's zorua!)
Celebi was an event during 2011 in Pokemon Soul Silver, Heart Gold, Pearl, Diamond, Platnium. But now it already passed. Maybe they'll get an event for Celebi for Pokemon Black and White. You can also use the Action Replay and get the code for Celebi.
If you have Celebi on Pokemon Diamond, Pearl, Platinum, HeartGold, or SoulSilver, you can use the PokeTransfer machine in Pokemon Black and White to transfer it.