Lost luggage is the phenomena where an airline does not send a passenger's luggage to the correct destination. In the United States and average of 1 in 250 pieces of checked baggage are misdirected each year.

Lost or misdirected luggage becomes more common the more elaborate a flight plan is. International flights, or flights with connections are far more likely to see luggage get lost. There are many causes of lost luggage. If a passenger arrives late for a flight luggage will sometimes not have enough time to be loaded on the plane. If tags are accidentally torn off airport workers may not know where to send the luggage. Human error is also common as tags are misread or luggage is placed in the wrong location.

Most lost luggage is quickly sent by the airline to the correct destination. For the inconvenience airlines will often give some money for toiletries, and sometimes perks such as a free seat upgrade. On some occasions luggage is completely lost and cannot be recovered. The airline will then normally compensate the owner. The passengers must then list the contents of their baggage and file a claim. The limits as to how much compensation one can receive vary from nation to nation, but on international flights it is limited to 9.07 US dollars per pound. Most airlines maintain stores where they sell the contents of lost or abandoned luggage.

To deal with lost luggage travelers are advised to carry all essentials in a carry-on bag, including a change of clothes and anything they would be greatly troubled to lose because of monetary or emotional value.