diff --git a/builder/proxmox/config.go b/builder/proxmox/config.go
index f1a86bebf..07512ca41 100644
--- a/builder/proxmox/config.go
+++ b/builder/proxmox/config.go
@@ -86,6 +86,7 @@ type diskConfig struct {
 	Size            string `mapstructure:"disk_size"`
 	CacheMode       string `mapstructure:"cache_mode"`
 	DiskFormat      string `mapstructure:"format"`
+	IOThread        bool   `mapstructure:"io_thread"`
 }
 type vgaConfig struct {
 	Type   string `mapstructure:"type"`
@@ -189,6 +190,17 @@ func (c *Config) Prepare(raws ...interface{}) ([]string, error) {
 			log.Printf("Disk %d cache mode not set, using default 'none'", idx)
 			c.Disks[idx].CacheMode = "none"
 		}
+		if c.Disks[idx].IOThread {
+			// io thread is only supported by virtio-scsi-single controller
+			if c.SCSIController != "virtio-scsi-single" {
+				errs = packer.MultiErrorAppend(errs, fmt.Errorf("io thread option requires virtio-scsi-single controller"))
+			} else {
+				// ... and only for virtio and scsi disks
+				if !(c.Disks[idx].Type == "scsi" || c.Disks[idx].Type == "virtio") {
+					errs = packer.MultiErrorAppend(errs, fmt.Errorf("io thread option requires scsi or a virtio disk"))
+				}
+			}
+		}
 		// For any storage pool types which aren't in rxStorageTypes in proxmox-api/proxmox/config_qemu.go:890
 		// (currently zfspool|lvm|rbd|cephfs), the format parameter is mandatory. Make sure this is still up to date
 		// when updating the vendored code!
diff --git a/builder/proxmox/config.hcl2spec.go b/builder/proxmox/config.hcl2spec.go
index b53b1239e..53055378b 100644
--- a/builder/proxmox/config.hcl2spec.go
+++ b/builder/proxmox/config.hcl2spec.go
@@ -230,6 +230,7 @@ type FlatdiskConfig struct {
 	Size            *string `mapstructure:"disk_size" cty:"disk_size" hcl:"disk_size"`
 	CacheMode       *string `mapstructure:"cache_mode" cty:"cache_mode" hcl:"cache_mode"`
 	DiskFormat      *string `mapstructure:"format" cty:"format" hcl:"format"`
+	IOThread        *bool   `mapstructure:"io_thread" cty:"io_thread" hcl:"io_thread"`
 }
 
 // FlatMapstructure returns a new FlatdiskConfig.
@@ -250,6 +251,7 @@ func (*FlatdiskConfig) HCL2Spec() map[string]hcldec.Spec {
 		"disk_size":         &hcldec.AttrSpec{Name: "disk_size", Type: cty.String, Required: false},
 		"cache_mode":        &hcldec.AttrSpec{Name: "cache_mode", Type: cty.String, Required: false},
 		"format":            &hcldec.AttrSpec{Name: "format", Type: cty.String, Required: false},
+		"io_thread":         &hcldec.AttrSpec{Name: "io_thread", Type: cty.Bool, Required: false},
 	}
 	return s
 }
diff --git a/builder/proxmox/config_test.go b/builder/proxmox/config_test.go
index e17d2e82f..39019b85e 100644
--- a/builder/proxmox/config_test.go
+++ b/builder/proxmox/config_test.go
@@ -208,3 +208,52 @@ func TestPacketQueueSupportForNetworkAdapters(t *testing.T) {
 		}
 	}
 }
+
+func TestHardDiskControllerIOThreadSupport(t *testing.T) {
+	drivertests := []struct {
+		expectedToFail bool
+		controller     string
+		disk_type      string
+	}{
+		// io thread is only supported by virtio-scsi-single controller
+		// and only for virtio and scsi disks
+		{expectedToFail: false, controller: "virtio-scsi-single", disk_type: "scsi"},
+		{expectedToFail: false, controller: "virtio-scsi-single", disk_type: "virtio"},
+		{expectedToFail: true, controller: "virtio-scsi-single", disk_type: "sata"},
+		{expectedToFail: true, controller: "lsi", disk_type: "scsi"},
+		{expectedToFail: true, controller: "lsi53c810", disk_type: "virtio"},
+	}
+
+	for _, tt := range drivertests {
+		nic := make(map[string]interface{})
+		nic["bridge"] = "vmbr0"
+
+		nics := make([]map[string]interface{}, 0)
+		nics = append(nics, nic)
+
+		disk := make(map[string]interface{})
+		disk["type"] = tt.disk_type
+		disk["io_thread"] = true
+		disk["storage_pool"] = "local-lvm"
+		disk["storage_pool_type"] = "lvm"
+
+		disks := make([]map[string]interface{}, 0)
+		disks = append(disks, disk)
+
+		cfg := mandatoryConfig(t)
+		cfg["network_adapters"] = nics
+		cfg["disks"] = disks
+		cfg["scsi_controller"] = tt.controller
+
+		var c Config
+		_, err := c.Prepare(cfg)
+
+		if tt.expectedToFail == true && err == nil {
+			t.Error("expected config preparation to fail, but no error occured")
+		}
+
+		if tt.expectedToFail == false && err != nil {
+			t.Errorf("expected config preparation to succeed, but %s", err.Error())
+		}
+	}
+}
diff --git a/builder/proxmox/step_start_vm.go b/builder/proxmox/step_start_vm.go
index c128fe44c..23ccfbf80 100644
--- a/builder/proxmox/step_start_vm.go
+++ b/builder/proxmox/step_start_vm.go
@@ -142,6 +142,10 @@ func generateProxmoxDisks(disks []diskConfig) proxmox.QemuDevices {
 		setDeviceParamIfDefined(devs[idx], "storage_type", disks[idx].StoragePoolType)
 		setDeviceParamIfDefined(devs[idx], "cache", disks[idx].CacheMode)
 		setDeviceParamIfDefined(devs[idx], "format", disks[idx].DiskFormat)
+
+		if devs[idx]["type"] == "scsi" || devs[idx]["type"] == "virtio" {
+			setDeviceParamIfDefined(devs[idx], "iothread", strconv.FormatBool(disks[idx].IOThread))
+		}
 	}
 	return devs
 }
diff --git a/website/pages/docs/builders/proxmox.mdx b/website/pages/docs/builders/proxmox.mdx
index acef9881e..1e3525bb4 100644
--- a/website/pages/docs/builders/proxmox.mdx
+++ b/website/pages/docs/builders/proxmox.mdx
@@ -185,6 +185,11 @@ builder.
     `raw`, `cow`, `qcow`, `qed`, `qcow2`, `vmdk` or `cloop`. Defaults to
     `raw`.
 
+  - `io_thread` (bool) - Create one I/O thread per storage controller, rather
+    than a single thread for all I/O. This can increase performance when
+    multiple disks are used. Requires `virtio-scsi-single` controller and a
+    `scsi` or `virtio` disk. Defaults to `false`.
+
 - `template_name` (string) - Name of the template. Defaults to the generated
   name used during creation.