Embodiments of the present invention provide a method, system and computer program product for collaborative route reservation in an HPC fabric. A method for collaborative route reservation in an HPC fabric includes selecting a target node in a cluster of nodes to receive a payload from a source node of the cluster over an HPC fabric and computing a route over the HPC fabric for transferring the payload from the source node to the target node, and also a duration of time requisite to transferring the payload. The method also includes notifying other nodes in the cluster of a reservation of the computed route for the duration of time and utilizing the computed route during the duration of time to transfer the payload. Finally, the method includes responding to completing transfer of the payload by notifying the other nodes that the computed path is no longer reserved.