diff --git a/.github/workflows/example-builds.yml b/.github/workflows/example-builds.yml
index 62caf58d..862fc369 100644
--- a/.github/workflows/example-builds.yml
+++ b/.github/workflows/example-builds.yml
@@ -27,6 +27,13 @@ jobs:
         exclude:
           - os: macOS-latest
             julia-arch: x86
+        include:
+          - os: macOS-latest
+            julia-arch: aarch64
+            julia-version: 'lts'
+          - os: macOS-latest
+            julia-arch: aarch64
+            julia-version: '1'
 
     steps:
       - uses: actions/checkout@v4
diff --git a/README.md b/README.md
index a20b3d50..045e39a6 100644
--- a/README.md
+++ b/README.md
@@ -194,12 +194,18 @@ jobs:
     strategy:
       matrix:
         julia-version: ['1.0', '1.2.0', '^1.3.0-rc1']
-        julia-arch: [x64, x86]
+        julia-arch: [x64, x86, aarch64]
         os: [ubuntu-latest, windows-latest, macOS-latest]
-        # 32-bit Julia binaries are not available on macOS
+        # exclude unavailable/unwanted architectures
         exclude:
           - os: macOS-latest
             julia-arch: x86
+          - os: macOS-latest
+            julia-arch: x64 # can be run but via rosetta on apple silicon runners
+          - os: ubuntu-latest
+            julia-arch: aarch64
+          - os: windows-latest
+            julia-arch: aarch64
 
     steps:
       - uses: actions/checkout@v4
diff --git a/dist/index.js b/dist/index.js
index fa1564be..638ebd1b 100644
--- a/dist/index.js
+++ b/dist/index.js
@@ -580,6 +580,9 @@ function run() {
             if (!originalArchInput) { // if `originalArchInput` is an empty string
                 throw new Error(`Arch input must not be null`);
             }
+            if (originalArchInput == 'x64' && os.platform() == 'darwin' && os.arch() == 'arm64') {
+                core.warning('[setup-julia] x64 arch has been requested on a macOS runner that has an arm64 (Apple Silicon) architecture. You may have meant to use the "aarch64" arch instead (or left it unspecified for the correct default).');
+            }
             let processedArchInput;
             if (originalArchInput == "default") {
                 // If the user sets the `arch` input to `default`, then we use the
diff --git a/lib/setup-julia.js b/lib/setup-julia.js
index 471adfd0..cb5e5c88 100644
--- a/lib/setup-julia.js
+++ b/lib/setup-julia.js
@@ -88,6 +88,9 @@ function run() {
             if (!originalArchInput) { // if `originalArchInput` is an empty string
                 throw new Error(`Arch input must not be null`);
             }
+            if (originalArchInput == 'x64' && os.platform() == 'darwin' && os.arch() == 'arm64') {
+                core.warning('[setup-julia] x64 arch has been requested on a macOS runner that has an arm64 (Apple Silicon) architecture. You may have meant to use the "aarch64" arch instead (or left it unspecified for the correct default).');
+            }
             let processedArchInput;
             if (originalArchInput == "default") {
                 // If the user sets the `arch` input to `default`, then we use the
diff --git a/src/setup-julia.ts b/src/setup-julia.ts
index 9ff3990a..587dc67b 100644
--- a/src/setup-julia.ts
+++ b/src/setup-julia.ts
@@ -62,6 +62,10 @@ async function run() {
             throw new Error(`Arch input must not be null`)
         }
 
+        if (originalArchInput == 'x64' && os.platform() == 'darwin' && os.arch() == 'arm64') {
+            core.warning('[setup-julia] x64 arch has been requested on a macOS runner that has an arm64 (Apple Silicon) architecture. You may have meant to use the "aarch64" arch instead (or left it unspecified for the correct default).')
+        }
+
         let processedArchInput: string;
         if (originalArchInput == "default") {
             // If the user sets the `arch` input to `default`, then we use the