R.T. S.
Yelp
I'm a big fan of Lolita's as one of very few late-night food and grocery options in Boulder. They used to be open even later than they currently are (24 hours), but apparently this college town can't support that kind of a business (?).
You will find basic necessities, like pet food, OTC medicines, dish soap, and other household and office/school items here, along with groceries (bread, fresh fruit, canned soups, mac'n'cheese, frozen dinners, vegetarian dinners, frozen pizzas, dairy and non-dairy milk, yogurt, cheese, bags of ice, etc). They have a wide variety of high quality, often organic snacks and drinks as well. Sodas, energy drinks, teas, coffees, water, kombucha, smoothies, and more, along with potato chips, crackers, corn chips, jerky, cookies, dairy and non-dairy ice cream, chocolate bars, candies, muffins, gluten-free breads and treats, etc.
I've never been here when the deli is open, but I often buy a late night meal from the fridge case to the far left of the store at the front, where the fresh-made deli items are kept. They have sandwiches and wraps, potato salad (yum!), different chicken salads (yum!), dolmas (stuffed grape leaves--also yum!), macaroni salad, hummus, and lots of other tasty, fresh food. I've always been really pleased with the quality and price of the deli items (I am pretty picky about my food and eat mostly organic). I can make myself a satisfying meal for about $13. Some of the items are gluten and/or dairy-free, and some are vegan.
Parking can be a hassle during the day, when it's usually super crowded on Pearl Street and when parking meters are in force, but later at night there's plenty of free parking near the store, along with a Little Free Library for you to browse. The store is well lit and Boulder is incredibly safe and I never feel uncomfortable coming here alone at night as a single woman.
The people who work here are always chill, which is nice. My only complaint is that everything is significantly more expensive than at any other grocery in town, including some of the organic/health food specialty groceries (this is understandable, considering the prime real estate the shop occupies). But if you really need good food or household supplies late at night, Lolita's has got you covered.