United Airlines frequently offers the most nonstop service from Newark Liberty International Airport (EWR) to Los Angeles (All Airports) (LAXA), with multiple daily flights and robust loyalty perks for MileagePlus members. Delta and American offer competitive one-stop and limited nonstop options in September, with SkyMiles and AAdvantage benefits for frequent flyers. JetBlue and Alaska may provide value-forward options or partner itineraries, while low-cost carriers sometimes operate connecting flights via other hubs. Choose United for convenience and nonstop availability, Delta for network connections and Delta One on select transcons, and low-cost options if price and flexibility matter most. For booking, compare baggage policies, seat selection fees, and onboard amenities before locking in your September fare. CTA: Compare current fares across carriers and review loyalty benefits to pick the best airline for your Newark to Los Angeles trip.