Ontario International Airport (ONT) served more than 2.75 million passengers during the first five months of 2026, a 2.3% increase from the same period last year.

The airport welcomed 632,441 passengers in May, up 0.4% from May 2025. Domestic traffic declined 2.3% to 577,523 passengers, while international passenger volume increased 41.5% to 54,918.

Year to date, ONT has served nearly 2.46 million domestic passengers, down 1.6% from the same period in 2025. International traffic increased 53.7% to 292,348 passengers.

“The continued growth in passenger traffic, especially among international travelers, reflects the strength of our market and the growing number of travelers who choose ONT as their preferred gateway to Southern California,” said Atif Elkadi, chief executive officer of the Ontario International Airport Authority.

Southwest Airlines accounted for the largest share of ONT passengers in May at 35.7%, followed by American Airlines at 14%, Delta Air Lines at 10.9%, Frontier Airlines at 10.1% and Alaska Airlines at 10%.

Cargo activity also increased during the month. ONT handled 73,561 tons of freight and mail in May, up 4.7% year over year. Freight volume increased 8.2% to 63,415 tons, while mail volume declined 13% to 10,145 tons.

Through May, total cargo volume increased 7.4% to nearly 357,000 tons. Freight grew 11.2% to more than 307,000 tons, while mail shipments declined 11.4%.