Pour the ranch dressing into the bottom of a clean 32-ounce wide-mouth mason jar.
Layer the cherry tomatoes and cucumbers directly on top of the dressing to create a moisture barrier.
Add the cubed grilled chicken and chopped bacon as the next layer.
Toss the diced avocado in lime juice to prevent oxidation, then add it to the jar.
Sprinkle the shredded cheddar cheese over the avocado layer.
Fill the remaining space in the jar with the chopped Romaine lettuce, packing it relatively tightly to minimize air gaps.
Seal the jar with a tight-fitting lid and refrigerate for up to 3 days.
To serve, shake the jar vigorously to distribute the dressing or invert the contents into a large bowl and toss.