Preheat your oven to 250°F (120°C). While the oven is warming up, prepare a large rimmed baking sheet by lining it with parchment paper or a silicone baking mat for easy cleanup.
In a small mixing bowl, whisk together the canola oil, the dry Ranch dressing mix, the dried dill weed, garlic powder, and lemon pepper until the mixture is well combined and the spices are evenly distributed throughout the oil.
Place the oyster crackers into a large mixing bowl. Pour the seasoned oil mixture over the crackers. Use a large spoon or spatula to gently toss the crackers until every single piece is thoroughly coated in the ranch seasoning.
Spread the coated crackers in a single layer on your prepared baking sheet. Place them in the oven and bake for 15 to 20 minutes. About halfway through the baking time, give the crackers a gentle stir to ensure they brown evenly and don’t stick together.
Remove the baking sheet from the oven and allow the crackers to cool completely on the pan. As they cool, the coating will set and the crackers will become extra crunchy. Once cooled, they are ready to serve!