As of September 2025, several airlines offer direct and connecting flights from Atlanta (ATL) to Denver (DEN). Nonstop service is available daily with a flight time of approximately 3 to 3.5 hours. 

Airlines with nonstop service

• Delta Air Lines: Offers frequent daily nonstop flights.
• Southwest Airlines: Provides multiple nonstop flights per week.
• United Airlines: Operates daily nonstop service on this route.
• Frontier Airlines: Offers nonstop flights, often with the lowest fares. 

Sample round-trip fares

Prices fluctuate based on the date of travel, how far in advance you book, and the airline. For example, a search for flights from late October 2025 shows: 

• Frontier: From ~$10,754 (or $107)
• Southwest: From ~$14,310 (or $140)
• United: From ~$13,837 (or $137)
• Delta: From ~$17,365 (or $175) 

Tips for booking

• Book in advance: Booking 2 weeks to 3 months before your trip can yield lower prices.
• Cheapest days: Flying on Tuesdays or Wednesdays is often cheaper than weekends.
• Consider low-cost carriers: For the cheapest fares, check Frontier, but be mindful of additional fees for bags and seat selection.
• Use price alerts: Websites like Google Flights and Skyscanner allow you to track prices and will notify you when fares rise or fall.