Whisk together sweet chili sauce and ranch dressing in a bowl.
Place chicken tenders in a gallon ziplock bag.
Pour the marinade over the chicken, seal the bag, and ensure all pieces are well-coated.
Refrigerate for at least 2 hours, preferably overnight.
Preheat the grill to medium-high heat.
Remove chicken from marinade, discard excess marinade.
Grill chicken tenders for about 10 minutes, turning occasionally, until fully cooked and slightly charred on the edges.