Is your return flight automatically cancelled if you no show for departure ?

[CupCrusher40]

Thank you !

[TheMiddleSeat]

If you completely no show all remaining flights on the same reservation will be canceled. If you arrive late, Southwest has an unwritten flat tire rule and will do its best to accommodate you on another flight. Typically this means you are put on standby for a later flight if one is available. Arriving late does not automatically mean you are out of luck with no option to fly. 

--TheMiddleSeat

[dfwskier]

Let's look at the rationale about why a return flight would be cancelled. It's really pretty simple.

If you no show for the outbound flight, how can the airline expect you to actually take the return flight? I mean if you don't get to the destination city, how can you depart from that city?

Now I've never had that happen to me because almost all reservations I make are one way reservations.