Methods are provided for ultra-wideband (UWB) ranging based on contention-based multiple access. A method performed by a first UWB device includes transmitting an initiation message for initiating UWB ranging, receiving an access message from a second UWB device within a contention period, transmitting a first reply message (RM), receiving a second RM corresponding to the first RM from the second UWB device, and transmitting a final message.