I'm fairly familiar with which Star Wars properties are/aren't considered Disney canon; I was thinking about it yesterday and realized that I can't think of a single appearance of the Chiss race in any canonical sense, aside from Legends. Do they appear in any Disney canon works, and if so, can you point me to them?
Yes - Both Chiss (and Admiral Thrawn!) are Disney canon.
Timothy Zahn's Disney Canon novel Thrawn introduces them.
Eli winced. A gift for the Chiss of the stories, that would have been a deadly insult. Thrawn was behind him, and he didn’t dare turn around, but he could imagine the expression on that proud face.
“I do, Your Majesty,” Parck said, bowing low. “A warrior reportedly of a race known as the Chiss.”
“Would I?” the Emperor sounded amused. “Certainly you’re a resource of unlimited confidence. What exactly do you offer, Chiss?”
Some relevant details from new Disney canon were summarized in Wookieepedia Chiss article.
As another answer noted, Thrawn (and his blue appearance) is also in Star Wars Rebels but I'm not aware if he's named as a Chiss there.
Since your question doesn't explicitly specify whether you meant Disney canon by "canon", I should for completeness's sake point out that Chiss are most certainly a part of EU Legends canon, in multiple books starting with Timothy Zahn's original trilogy.
According to Wookieepedia
The Chiss became canon when they appeared in Secret Alliances, the sixth campaign featured in Star Wars: Commander, a mobile game published by Disney Interactive1 that was released on August 21, 2014.
Also from StarWars.com - Grand Admiral Thrawn
Thrawn was a male Chiss, with striking blue skin, red eyes, and an angular face, known for his brilliant strategic mind and ruthlessness. He was determined to “pull the rebels apart piece by piece.”