diff --git a/packages/gatsby-cli/README.md b/packages/gatsby-cli/README.md
index 5010b610ba401..f97fe8cbf8790 100644
--- a/packages/gatsby-cli/README.md
+++ b/packages/gatsby-cli/README.md
@@ -78,12 +78,12 @@ development server.
 
 #### Options
 
-|     Option      | Description                                     |       Default        |
-| :-------------: | ----------------------------------------------- | :------------------: |
-| `-H`, `--host`  | Set host.                                       |     `localhost`      |
-| `-p`, `--port`  | Set port.                                       | `env.PORT` or `8000` |
-| `-o`, `--open`  | Open the site in your (default) browser for you |                      |
-| `-S`, `--https` | Use HTTPS                                       |                      |
+|     Option      | Description                                     |          Default          |
+| :-------------: | ----------------------------------------------- | :-----------------------: |
+| `-H`, `--host`  | Set host.                                       | `env.HOST` or `localhost` |
+| `-p`, `--port`  | Set port.                                       |   `env.PORT` or `8000`    |
+| `-o`, `--open`  | Open the site in your (default) browser for you |                           |
+| `-S`, `--https` | Use HTTPS                                       |                           |
 
 Follow the [Local HTTPS guide](https://www.gatsbyjs.org/docs/local-https/)
 to find out how you can set up an HTTPS development server using Gatsby.
diff --git a/packages/gatsby-cli/src/create-cli.ts b/packages/gatsby-cli/src/create-cli.ts
index dcee342521f69..ede5a1e61b23a 100644
--- a/packages/gatsby-cli/src/create-cli.ts
+++ b/packages/gatsby-cli/src/create-cli.ts
@@ -144,8 +144,10 @@ function buildLocalCommands(cli: yargs.Argv, isLocalSite: boolean): void {
       _.option(`H`, {
         alias: `host`,
         type: `string`,
-        default: defaultHost,
-        describe: `Set host. Defaults to ${defaultHost}`,
+        default: process.env.HOST || defaultHost,
+        describe: process.env.HOST
+          ? `Set host. Defaults to ${process.env.HOST} (set by env.HOST) (otherwise defaults ${defaultHost})`
+          : `Set host. Defaults to ${defaultHost}`,
       })
         .option(`p`, {
           alias: `port`,