The Prometheus Operator supports a number of Kubernetes and Prometheus releases.
The Prometheus Operator uses client-go to communicate with Kubernetes clusters. The supported Kubernetes cluster version is determined by client-go. The compatibility matrix for client-go and Kubernetes clusters can be found here. All additional compatibility is only best effort, or happens to still/already be supported. The currently used client-go version is "v4.0.0-beta.0".
The versions of Prometheus compatible to be run with the Prometheus Operator are: