diff --git a/docs/resources/virtualization_vm.md b/docs/resources/virtualization_vm.md
index 53460765b..df971318b 100644
--- a/docs/resources/virtualization_vm.md
+++ b/docs/resources/virtualization_vm.md
@@ -16,6 +16,15 @@ resource "netbox_virtualization_vm" "vm_test" {
     name = "tag1"
     slug = "tag1"
   }
+
+  custom_fields = {
+    cf_boolean = "true"
+    cf_date = "2020-12-25"
+    cf_integer = "10"
+    cf_selection = "1"
+    cf_text = "Some text"
+    cf_url = "https://github.com"
+  }
 }
 ```
 
@@ -36,6 +45,13 @@ The following arguments are supported:
 The ``tag`` block supports:
 * ``name`` - (Required) Name of the existing tag to associate with this resource.
 * ``slug`` - (Required) Slug of the existing tag to associate with this resource.
+* ``custom_fields`` - (Optional) Custom Field Keys and Values for this object
+** For boolean, use the string value "true" or "false"
+** For data, use the string format "YYYY-MM-DD"
+** For integer, use the value between double quote "10"
+** For selection, use the level id
+** For text, use the string value
+** For URL, use the URL as string
 
 ## Attributes Reference
 
diff --git a/netbox/resource_netbox_virtualization_vm.go b/netbox/resource_netbox_virtualization_vm.go
index 74369dd50..de5ef7ee7 100644
--- a/netbox/resource_netbox_virtualization_vm.go
+++ b/netbox/resource_netbox_virtualization_vm.go
@@ -90,6 +90,24 @@ func resourceNetboxVirtualizationVM() *schema.Resource {
 				Optional: true,
 				Default:  0,
 			},
+			"custom_fields": {
+				Type:     schema.TypeMap,
+				Optional: true,
+				Elem: &schema.Schema{
+					Type: schema.TypeString,
+				},
+				// terraform default behavior sees a difference between null and an empty string
+				// therefore we override the default, because null in terraform results in empty string in netbox
+				DiffSuppressFunc: func(k, old, new string, d *schema.ResourceData) bool {
+					// function is called for each member of map
+					// including additional call on the amount of entries
+					// we ignore the count, because the actual state always returns the amount of existing custom_fields and all are optional in terraform
+					if k == "custom_fields.%" {
+						return true
+					}
+					return old == new
+				},
+			},
 		},
 	}
 }
@@ -110,6 +128,8 @@ func resourceNetboxVirtualizationVMCreate(d *schema.ResourceData,
 	tags := d.Get("tag").(*schema.Set).List()
 	tenantID := int64(d.Get("tenant_id").(int))
 	vcpus := int64(d.Get("vcpus").(int))
+	resourceCustomFields := d.Get("custom_fields").(map[string]interface{})
+	customFields := convertCustomFieldsFromTerraformToAPICreate(resourceCustomFields)
 
 	newResource := &models.WritableVirtualMachineWithConfigContext{
 		Cluster:          &clusterID,
@@ -144,6 +164,8 @@ func resourceNetboxVirtualizationVMCreate(d *schema.ResourceData,
 		newResource.Vcpus = &vcpus
 	}
 
+	newResource.CustomFields = &customFields
+
 	resource := virtualization.NewVirtualizationVirtualMachinesCreateParams().WithData(newResource)
 
 	resourceCreated, err := client.Virtualization.VirtualizationVirtualMachinesCreate(resource, nil)
@@ -247,6 +269,12 @@ func resourceNetboxVirtualizationVMRead(d *schema.ResourceData,
 				return err
 			}
 
+			customFields := convertCustomFieldsFromAPIToTerraform(resource.CustomFields)
+
+			if err = d.Set("custom_fields", customFields); err != nil {
+				return err
+			}
+
 			return nil
 		}
 	}
@@ -314,6 +342,13 @@ func resourceNetboxVirtualizationVMUpdate(d *schema.ResourceData,
 		params.Vcpus = &vcpus
 	}
 
+	//
+	if d.HasChange("custom_fields") {
+		stateCustomFields, resourceCustomFields := d.GetChange("custom_fields")
+		customFields := convertCustomFieldsFromTerraformToAPIUpdate(stateCustomFields, resourceCustomFields)
+		params.CustomFields = &customFields
+	}
+
 	resource := virtualization.NewVirtualizationVirtualMachinesPartialUpdateParams().WithData(params)
 
 	resourceID, err := strconv.ParseInt(d.Id(), 10, 64)
diff --git a/netbox/util.go b/netbox/util.go
index db9343a28..607813fa8 100644
--- a/netbox/util.go
+++ b/netbox/util.go
@@ -230,3 +230,66 @@ func updatePrimaryStatus(m interface{}, info InfosForPrimary, id int64) error {
  *   return customFieldsAPI
  * }
  */
+
+// custom_fields have multiple data type returns based on field type
+// but terraform only supports map[string]string, so we convert all to strings
+func convertCustomFieldsFromAPIToTerraform(customFields interface{}) map[string]string {
+	toReturn := make(map[string]string)
+	switch t := customFields.(type) {
+	case map[string]interface{}:
+		for key, value := range t {
+			var strValue string
+			if value != nil {
+				switch v := value.(type) {
+				default:
+					strValue = fmt.Sprintf("%v", v)
+				case map[string]interface{}:
+					strValue = fmt.Sprintf("%v", v["value"])
+				}
+			}
+			toReturn[key] = strValue
+
+		}
+	}
+
+	return toReturn
+}
+
+func convertCustomFieldsFromTerraformToAPICreate(customFields map[string]interface{}) map[string]interface{} {
+	toReturn := make(map[string]interface{})
+	for key, value := range customFields {
+		toReturn[key] = value
+
+		// special handling for booleans, as they are the only parameter not supplied as string to netbox
+		if value == "true" {
+			toReturn[key] = 1
+		} else if value == "false" {
+			toReturn[key] = 0
+		}
+	}
+
+	return toReturn
+}
+
+// all custom fields need to be submitted to the netbox API for updates
+func convertCustomFieldsFromTerraformToAPIUpdate(stateCustomFields, resourceCustomFields interface{}) map[string]interface{} {
+	toReturn := make(map[string]interface{})
+
+	// netbox needs explicit empty string to remove old values
+	// first we fill all existing fields from the state with an empty string
+	for key := range stateCustomFields.(map[string]interface{}) {
+		toReturn[key] = nil
+	}
+	// then we override the values that still exist in the terraform code with their respective value
+	for key, value := range resourceCustomFields.(map[string]interface{}) {
+		toReturn[key] = value
+
+		// special handling for booleans, as they are the only parameter not supplied as string to netbox
+		if value == "true" {
+			toReturn[key] = 1
+		} else if value == "false" {
+			toReturn[key] = 0
+		}
+	}
+	return toReturn
+}