diff --git a/completers/molecule_completer/cmd/action/host.go b/completers/molecule_completer/cmd/action/host.go
new file mode 100644
index 0000000000..48e8a46a92
--- /dev/null
+++ b/completers/molecule_completer/cmd/action/host.go
@@ -0,0 +1,106 @@
+package action
+
+import (
+	"os"
+	"path"
+	"time"
+
+	"github.com/carapace-sh/carapace"
+	"github.com/carapace-sh/carapace-bin/pkg/actions/net"
+	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v3"
+)
+
+// ActionInstances completes known host names and known molecule instance hosts
+func ActionInstances(cmd *cobra.Command) carapace.Action {
+	return carapace.Batch(
+		net.ActionHosts(),
+		carapace.ActionValuesDescribed(getInstances(cmd)...).Cache(time.Minute),
+	).ToA()
+}
+
+// Get active instances
+func getInstances(cmd *cobra.Command) []string {
+	ephemeralPath := getMoleculeEphemeralDir(cmd)
+
+	cwd, err := os.Getwd()
+	if err != nil {
+		return []string{}
+	}
+	roleName := path.Base(cwd)
+
+	scenarioName, err := cmd.Flags().GetString("scenario-name")
+	if err != nil {
+		scenarioName = "default"
+	}
+
+	inventoryPath := path.Join(ephemeralPath, roleName, scenarioName, "inventory", "ansible_inventory.yml")
+	inventoryData, err := os.ReadFile(inventoryPath)
+	if err != nil {
+		return []string{}
+	}
+
+	var inventoryMap struct {
+		all struct {
+			hosts map[string]struct {
+				ansibleHost string `yaml:"ansible_host"`
+			}
+		}
+	}
+	if err := yaml.Unmarshal(inventoryData, &inventoryMap); err != nil {
+		return []string{}
+	}
+
+	inventory := make([]string, 0)
+	for host, hostData := range inventoryMap.all.hosts {
+		inventory = append(inventory, hostData.ansibleHost, host)
+	}
+
+	return inventory
+}
+
+// Find the location molecule is storing ephemeral data
+func getMoleculeEphemeralDir(cmd *cobra.Command) string {
+	// Default to the platform equivalent to "$HOME" joined with .cache/molecule"
+	// (molecule does not support windows)
+	ephemeralPath, err := os.UserHomeDir()
+	if err != nil {
+		return ""
+	}
+	ephemeralPath = path.Join(ephemeralPath, ".cache", "molecule")
+
+	// Check for more specific cache directory environment variable
+	if cacheHome, ok := os.LookupEnv("XDG_CACHE_HOME"); ok {
+		ephemeralPath = path.Join(cacheHome, "molecule")
+	}
+
+	// Check for specific molecule environment variable
+	if moleculeEphemeral, ok := os.LookupEnv("MOLECULE_EPHEMERAL_DIRECTORY"); ok {
+		ephemeralPath = moleculeEphemeral
+	}
+
+	// Check for path specified in molecule .env.yml file
+	// GetString defaults to the correct value (.env.yml)
+	envFilePath, err := cmd.Flags().GetString("env-file")
+	if err != nil {
+		envFilePath = ".env.yml"
+	}
+
+	envData, err := os.ReadFile(envFilePath)
+	if err != nil {
+		return ephemeralPath
+	}
+
+	envMap := make(map[string]any)
+	if err := yaml.Unmarshal(envData, envMap); err != nil {
+		return ephemeralPath
+	}
+
+	if moleculeEphemeral, ok := envMap["MOLECULE_EPHEMERAL_DIRECTORY"]; ok {
+		if s, ok := moleculeEphemeral.(string); ok {
+			ephemeralPath = s
+		}
+	}
+
+	return ephemeralPath
+}
diff --git a/completers/molecule_completer/cmd/login.go b/completers/molecule_completer/cmd/login.go
index 386e983b39..153b6d1c75 100644
--- a/completers/molecule_completer/cmd/login.go
+++ b/completers/molecule_completer/cmd/login.go
@@ -2,6 +2,7 @@ package cmd
 
 import (
 	"github.com/carapace-sh/carapace"
+	"github.com/carapace-sh/carapace-bin/completers/molecule_completer/cmd/action"
 	"github.com/carapace-sh/carapace-bin/pkg/actions/tools/molecule"
 	"github.com/spf13/cobra"
 )
@@ -20,7 +21,7 @@ func init() {
 	loginCmd.Flags().StringP("scenario-name", "s", "default", "Name of the scenario to target")
 
 	carapace.Gen(loginCmd).FlagCompletion(carapace.ActionMap{
-		// "host":          action.ActionInstances(loginCmd), // TODO
+		"host":          action.ActionInstances(loginCmd),
 		"scenario-name": molecule.ActionScenarios(),
 	})
 
diff --git a/pkg/actions/tools/molecule/host.go b/pkg/actions/tools/molecule/host.go
new file mode 100644
index 0000000000..b05d75dbfc
--- /dev/null
+++ b/pkg/actions/tools/molecule/host.go
@@ -0,0 +1,95 @@
+package molecule
+
+import (
+	"os"
+	"path"
+
+	"github.com/carapace-sh/carapace"
+	"gopkg.in/yaml.v3"
+)
+
+type InstanceOpts struct {
+	Scenario string
+	EnvFile  string
+}
+
+// ActionInstances completes known host names and known molecule instance hosts
+func ActionInstances(opts InstanceOpts) carapace.Action {
+	return carapace.ActionCallback(func(c carapace.Context) carapace.Action {
+		ephemeralPath := getMoleculeEphemeralDir(opts.EnvFile)
+		roleName := path.Base(c.Dir)
+
+		if opts.Scenario == "" {
+			opts.Scenario = "default"
+		}
+
+		inventoryPath := path.Join(ephemeralPath, roleName, opts.Scenario, "inventory", "ansible_inventory.yml")
+		inventoryData, err := os.ReadFile(inventoryPath)
+		if err != nil {
+			return carapace.ActionMessage(err.Error())
+		}
+
+		var inventoryMap struct {
+			all struct {
+				hosts map[string]struct {
+					ansibleHost string `yaml:"ansible_host"`
+				}
+			}
+		}
+		if err := yaml.Unmarshal(inventoryData, &inventoryMap); err != nil {
+			return carapace.ActionMessage(err.Error())
+		}
+
+		inventory := make([]string, 0)
+		for host, hostData := range inventoryMap.all.hosts {
+			inventory = append(inventory, hostData.ansibleHost, host)
+		}
+
+		return carapace.ActionValues(inventory...)
+	})
+}
+
+// Find the location molecule is storing ephemeral data
+func getMoleculeEphemeralDir(envFilePath string) string {
+	// Default to the platform equivalent to "$HOME" joined with .cache/molecule"
+	// (molecule does not support windows)
+	ephemeralPath, err := os.UserHomeDir()
+	if err != nil {
+		return ""
+	}
+	ephemeralPath = path.Join(ephemeralPath, ".cache", "molecule")
+
+	// Check for more specific cache directory environment variable
+	if cacheHome, ok := os.LookupEnv("XDG_CACHE_HOME"); ok {
+		ephemeralPath = path.Join(cacheHome, "molecule")
+	}
+
+	// Check for specific molecule environment variable
+	if moleculeEphemeral, ok := os.LookupEnv("MOLECULE_EPHEMERAL_DIRECTORY"); ok {
+		ephemeralPath = moleculeEphemeral
+	}
+
+	// Check for path specified in molecule .env.yml file
+	// GetString defaults to the correct value (.env.yml)
+	if envFilePath == "" {
+		envFilePath = ".env.yml"
+	}
+
+	envData, err := os.ReadFile(envFilePath)
+	if err != nil {
+		return ephemeralPath
+	}
+
+	envMap := make(map[string]any)
+	if err := yaml.Unmarshal(envData, envMap); err != nil {
+		return ephemeralPath
+	}
+
+	if moleculeEphemeral, ok := envMap["MOLECULE_EPHEMERAL_DIRECTORY"]; ok {
+		if s, ok := moleculeEphemeral.(string); ok {
+			ephemeralPath = s
+		}
+	}
+
+	return ephemeralPath
+}