_Panthera tigris_
Here's why:
* Genus: *Panthera* is the genus to which tigers belong, along with lions, leopards, and jaguars.
* Species: *tigris* is the specific species within the genus *Panthera* that refers to tigers.
* Italics: Scientific names are always written in italics.
* Capitalization: The genus name is capitalized, while the species name is not.
Therefore, the full scientific name for tigers is *Panthera tigris*.