Kubernetes offers three main scaling strategies for containerized applications: Horizontal Pod Autoscaling (HPA) increases or decreases pod replicas based on resource usage like CPU and memory; Vertical Pod Autoscaling (VPA) adjusts individual pod resource limits and requests; and Cluster Autoscaling manages the number of worker nodes in the cluster. HPA works best for stateless applications, VPA suits workloads with variable resource needs, and Cluster Autoscaler ensures infrastructure scales with demand. Each strategy addresses different scaling needs and can be combined for comprehensive auto-scaling solutions.