Choosing direct nonstop flights from Chicago O'Hare International (ORD) to Dublin Airport (DUB) in December reduces travel time and connection risk, making them ideal for holiday travelers who prioritize reliability. However, nonstop seats can be pricier; connecting flights via London (LHR), Amsterdam (AMS), Reykjavik (KEF), or Toronto (YYZ) often lower fares and add routing flexibility. In December, connecting itineraries increase the risk of missed connections due to weather or delays at ORD, so allow longer layovers and book through-tickets to ensure baggage protection. Use primary keywords like 'nonstop ORD to DUB' and 'one-stop Chicago Dublin' when comparing options to capture relevant fare deals.