How Do I Get Kecleon In Pokemon Platinum?

It can be found in the Great marsh in pastoria city, you need the national pokedex, you can find it at day, I hoe I help :)

You can find it in the great marsh. It it a day pokemon, so it's found in the day. But you have to look form the top floor with the machine you pay 100 to see in.

By the way the people who are saying it is in the great marsh are telling the truth(or atleast it worked for me anyway)

If my memory's correct I recall seeing a trainer while going to the survival area from the fight area once you,ve battled her check its area from your pokedex
(Hint:she,s an ace trainer.)