One big distinction The Legend of Zelda: Tears of the Kingdom has to its predecessor is that there are way more armor sets for Link to try on. This includes the Yiga Armor, which can transform Link into a henchman of his sworn enemies. While two of the armor pieces are in somewhat obvious places, though, the Yiga Tights are stuck away in a fairly obscure part of Hyrule.
Where to find the Yiga Tights (Pants) in TOTK - Zelda Tears of the Kingdom
The Yiga Tights in Tears of the Kingdom are in a cave to the north of Hyurle. This cave is home to The Yiga Clan Maritta Branch (coordinates: -0642, 2038, 0158), and it can be found in front of Mount Drena, where the Hebra region meets the north or Hyrule by the Forgotten Temple. If approaching from the south, players can easily see Yiga stones guiding the way.
The quickest way to get to this cave is to warp to the Kiuyoyou Shrine and walk north. It might be a good idea to Autobuild a vehicle just to make traveling quicker.
Once inside the cave, players will meet two members of the Yiga Clan who, like the rest of them, will challenge Link to combat. Whenever I fight these guys, I always take out the smaller one with the Duplex Bow first. That Yiga member always has less health than the bigger one with the Eightfold Longblade.
This cave has a couple other rooms to explore, but the Yiga Tights are right above where Link fights the Yiga Clan members. Just Ascend up there and talk to the Hateno tailor to receive the Yiga Tights.
Related: How to get Ember Armor in TOTK (Zelda Tears of the Kingdom)
Where to get the Yiga set armor in TOTK - Zelda Tears of the Kingdom
As for the other items in the Yiga armor set, the shirt can be found in the Ancient Akkala Lab (coordinates: 4511, 3154, 0247). This area is basically in the northeast corner of Hyrule, just north of East Akkala Stable. To get inside, players will need to travel to the Kawisar Lightroot in The Depths and use the pillar to Ascend into the building.
The Yiga mask is found on The Great Plateau in the old shack where the old man used to rest in Breath of the Wild (coordinates: -0792, -2256, 0087). This shack is on the eastern side of the Temple of Time ruins, but it's covered in spikes. Players will either need to glide from the Hyrule Field Skyview Tower or from on top of the Temple of Time Ruins to get inside.
Want more Zelda Tears of the Kingdom guides? Pro Game Guides has you covered with How to Get Froggy Armor to Climb Wet Surfaces in Zelda Tears of the Kingdom (TOTK).