Yes. At the time of writing, there were no animal-based ingredients used in manufacturing, so Skittles are Halal.
Skittles are chewy sweets in a crisp sugar shell with fruit flavours made by Mars Incorporated. They are considered Halal by Muslim dietary laws.
Skittles Ingredients for 2022:
Sugar, Glucose Syrup, Palm Fat, Acids Citric Acid, Malic Acid, Dextrin, Maltodextrin, Flavourings, Modified Starch, Colours E162, E163, E170, E160a, E100, E100, E132, E133, Acidity Regulator, Trisodium Citrate, Glazing Agent Carnauba Wax.