Although to be fair, you have nothing on the Māori of New Zealand. They named a hill Taumata­whakatangihanga­koauau­o­tamatea­turi­pukaka­piki­maunga­horo­nuku­pokai­whenua­ki­tana­tahu. That’s even longer than the town of Llanfairpwllgwyngyllgogerychwyrndrobwllllantysiliogogogoch in Wales.

Edit: None of them, though, come close to Ancient Greek’s lopado­temacho­selacho­galeo­kranio­leipsano­drim­hypo­trimmato­silphio­karabo­melito­katakechy­meno­kichl­epi­kossypho­phatto­perister­alektryon­opte­kephallio­kigklo­peleio­lagoio­siraio­baphe­tragano­pterygon, “a fictional dish originating from Aristophanes’ 391 B.C. comedy Assemblywomen.”

https://en.wikipedia.org/wiki/Lopado­temacho­selacho­galeo­kranio­leipsano­drim­hypo­trimmato­silphio­karabo­melito­katakechy­meno­kichl­epi­kossypho­phatto­perister­alektryon­opte­kephallio­kigklo­peleio­lagoio­siraio­baphe­tragano­pterygon