No, Singapore Air Does Not Have A 24-Hour Cancellation Policy. Singapore Airlines Cancellation Policy Depending On The Flight And Booking,Flight Changes And Cancellations Will Incur Charges As Stated In The Fare Conditions Of The Ticket. Cancellation Charges Vary And May Be Non-Refundable Depending On The Fare Purchased. It Is Advisable For Passengers To Contact Singapore Air's Customer Service For More Information On Applicable Charges. Singapore Airlines Offers A Flexible Cancellation Policy. Customers Have The Option To Cancel Their Flight Up To 24 Hours Before The Scheduled Departure Time And Receive A Full Refund. Refunds May Take Up To 7 Days To Process. Customers Who Cancel Their Flight After The 24-Hour Mark, Or Who Miss Their Flight, Will Not Receive A Refund. However, They May Be Able To Receive A Credit To Use Toward A Future Flight With Singapore Airlines.