An apparatus and method for supporting Quality of Service (QoS) in a wideband wireless communication system using multiple Frequency Allocations (FAs) are provided. In a transmitting method for packet distribution in the wideband wireless communication system, the method includes, during a network entry process, determining a number of FAs through multi-FA capability negotiation; distributing packets, received from a superordinate layer, through the multiple FAs; and transmitting the packets distributed through the multiple FAs. Accordingly, packets can be effectively distributed through multiple FAs, and QoS can be effectively provided.