Cheap Flights To Ontario (ONT) | 2026 Deals, Routes & Tips

Finding Cheap Flights To Ontario

Ontario is served by Ontario International Airport (ONT), a major airport in the Inland Empire region of Southern California. It has grown as a key alternative to Los Angeles International (LAX), focusing on domestic and international leisure arrivals, with a strong presence from low-cost and ultra-low-cost carriers.

The airport provides extensive domestic connectivity from major hubs and popular cities across the United States, including Seattle, Denver, Dallas, Chicago, and Atlanta. It also receives a significant number of flights from Mexico and seasonal services from other international destinations. Key arrival routes include high-frequency services from the Pacific Northwest and the Southwest.

Ontario International is a major base for Southwest Airlines for incoming flights and sees significant operations from American Airlines and Delta Air Lines. Ultra-low-cost carriers Spirit Airlines and Frontier Airlines have a strong presence. International carriers like Volaris and Aeroméxico provide service from Mexico into Ontario.

To find cheap flights to Ontario, book domestic arrivals 1-2 months in advance, using Southwest for value or Spirit/Frontier for low base fares (plus fees). For international travel from Mexico, book 2-3 months ahead. Use flight comparison tools. Flying on weekdays (Tuesday-Thursday) is significantly cheaper. ONT is known for having lower fares and less congestion than LAX for many domestic arrival routes. For a wider selection of long-haul international flights, LAX is still necessary, but Ontario excels for convenient, affordable arrivals within North America.