Prepare all your ingredients. Peel and finely dice the yellow onion, chop the hard-boiled eggs, and measure out the mayonnaise, chili sauce, Worcestershire sauce, and other components.
In a medium mixing bowl, add the mayonnaise, diced onion, small diced pickles, pimentos, chopped hard-boiled eggs, chili sauce, Worcestershire sauce, white vinegar, hot sauce, sugar, sea salt, and cracked black pepper.
Using a whisk or spoon, combine all the ingredients until they are well-mixed and creamy. Taste the dressing and adjust seasonings as needed.
Transfer your Homemade Thousand Island Dressing to a storage container and let it chill in the refrigerator for at least 30 minutes before serving.