Abstract: A method and system for an improved input/output (I/O) request quality of service (QoS) across multiple host I/O ports are disclosed. In one example, an I/O request associated with a classification parameter is received. The I/O request is generated by one of a plurality of host servers. Further, a classification value is determined based on the classification parameter by a host tagging agent residing one of the plurality of host servers. Furthermore, the classification value is associated with the I/O request by the host tagging agent. In addition, the I/O request is prioritized based on the classification value by a host port queuing manager and a host QoS controller. Based on the priority, the I/O request is sent to one of a plurality of target devices by the host port queuing manager and the host QoS controller.