Overview
Ontario sits in California's Inland Empire, around 35 miles east of downtown Los Angeles, at the foot of the San Gabriel Mountains. It's a relaxed, often overlooked base for exploring Southern California - within easy reach of LA, Orange County's theme parks and the desert resorts of Palm Springs - and usually comes with far lighter airport queues than LAX. For UK travellers after sunshine, Route 66 heritage and an easy road-trip start to a Southern California holiday, Ontario is a smart choice.
Best time to fly to Ontario
Ontario enjoys a classic Southern California climate: hot, dry summers and mild, largely rain-free winters. Late spring (April-May) and autumn (September-November) tend to be the sweet spot, with warm days, cooler evenings and fewer crowds than peak summer. July and August can be uncomfortably hot inland, while December to February brings the coolest temperatures and the odd rain shower, but plenty of clear days too. Check the When to book chart above to see where fares tend to dip.
Airlines and routes
There are no direct flights from the UK to Ontario International Airport, so journeys involve a connection. Most travellers fly non-stop from London or another UK city to a major US gateway - Los Angeles, Denver, Dallas/Fort Worth or Phoenix are common options - with carriers such as British Airways, Virgin Atlantic, American Airlines, United and Delta operating the transatlantic leg, then pick up a short domestic hop to Ontario. The transatlantic flight alone takes around 10-11 hours, so allow roughly 13-15 hours door to door with the connection. Flying into LAX and driving the final 35-40 miles is another popular option, and can work out just as quick.
Things to do in Ontario
Ontario is compact, but it's perfectly placed for day trips across the Inland Empire and beyond.
- Ontario Mills: one of Southern California's largest outlet and entertainment complexes, great for shopping and dining.
- Graber Olive House: a working olive-curing operation dating back to the 1890s, with tastings and local history.
- Mount Baldy: the highest peak in the San Gabriel Mountains, under an hour away, with hiking in summer and light skiing in winter.
- Route 66 heritage sites: Ontario sits on the historic route, with nostalgic diners, murals and small museums along the way.
- Disneyland and Anaheim: around 30 miles south-west, an easy day trip for families.
At Ontario International Airport (ONT)
ONT is only around two miles from downtown Ontario, so transfers are quick. Los Angeles city centre is roughly 35-40 miles away, typically a 45-minute to 1.5-hour drive on the I-10 depending on traffic. Car hire is the most flexible way to explore the region, with all major firms based at the airport; taxis, rideshares and the Metrolink commuter rail also serve travellers without a car.
Top tips for finding cheap flights to Ontario
- Book ahead: fares to Southern California are usually at their best around three to six months before departure.
- Fly midweek: Tuesday and Wednesday departures are typically cheaper than weekend flights.
- Stay flexible on dates: shifting by a few days either side of school holidays can bring fares down noticeably.
- Compare airlines and routings: use the price charts on this page to see which gateway and carrier combination suits your dates best.
Travel essentials
UK passport holders travelling for tourism or short business trips don't need a visa for stays of up to 90 days, but must apply for ESTA authorisation online before departure under the US Visa Waiver Programme. The currency is the US Dollar, and cards are widely accepted, though it's worth carrying some cash. No specific vaccinations are required, but comprehensive travel insurance with US medical cover is strongly recommended given the cost of healthcare in America.
