diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 8f7b30b0df..dfd57d3d3c 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -164,8 +164,11 @@ jobs:
           - # Default
 
         target:
-          - aarch64-apple-ios
           - aarch64-apple-darwin
+          - aarch64-apple-ios
+          # - aarch64-apple-tvos      Tier 3; handled below
+          # - aarch64-apple-visionos  Tier 3; handled below
+          # - aarch64-apple-watchos   Tier 3; handled below
           - aarch64-linux-android
           - aarch64-pc-windows-msvc
           - aarch64-unknown-linux-gnu
@@ -205,6 +208,28 @@ jobs:
             # TODO: Run in the emulator.
             cargo_options: --no-run
 
+          - target: aarch64-apple-tvos
+            host_os: macos-14
+            rust_channel: nightly
+            mode: --release
+            # TODO: Run in the emulator.
+            cargo_options: --no-run -Z build-std
+
+          - target: aarch64-apple-visionos
+            host_os: macos-14
+            rust_channel: nightly
+            mode: --release
+            xcode_version: 15.2
+            # TODO: Run in the emulator.
+            cargo_options: --no-run -Z build-std
+
+          - target: aarch64-apple-watchos
+            host_os: macos-14
+            rust_channel: nightly
+            mode: --release
+            # TODO: Run in the emulator.
+            cargo_options: --no-run -Z build-std
+
           - target: aarch64-linux-android
             host_os: ubuntu-22.04
             # TODO: https://github.com/briansmith/ring/issues/486
@@ -316,6 +341,9 @@ jobs:
           echo "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Tools\Llvm\x64\bin" >> $GITHUB_PATH
         shell: bash
 
+      - if: ${{ matrix.xcode_version != '' }}
+        run: sudo xcode-select -s /Applications/Xcode_${{ matrix.xcode_version }}.app
+
       - if: ${{ !contains(matrix.host_os, 'windows') }}
         run: |
           mk/cargo.sh +${{ matrix.rust_channel }} test -vv --target=${{ matrix.target }} ${{ matrix.cargo_options }} ${{ matrix.features }} ${{ matrix.mode }}
diff --git a/Cargo.toml b/Cargo.toml
index 0898ddd1af..0319c521fc 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -161,9 +161,12 @@ untrusted = { version = "0.9" }
 [target.'cfg(any(target_arch = "aarch64", target_arch = "arm", target_arch = "x86",target_arch = "x86_64"))'.dependencies]
 spin = { version = "0.9.8", default-features = false, features = ["once"] }
 
-[target.'cfg(all(any(target_os = "android", target_os = "linux", any(target_os = "ios", target_os = "macos", target_os = "tvos")), any(target_arch = "aarch64", target_arch = "arm")))'.dependencies]
+[target.'cfg(all(any(target_arch = "aarch64", target_arch = "arm"), any(target_os = "android", target_os = "linux")))'.dependencies]
 libc = { version = "0.2.148", default-features = false }
 
+[target.'cfg(all(target_arch = "aarch64", target_vendor = "apple", any(target_os = "ios", target_os = "macos", target_os = "tvos", target_os = "visionos", target_os = "watchos")))'.dependencies]
+libc = { version = "0.2.155", default-features = false }
+
 [target.'cfg(all(target_arch = "aarch64", target_os = "windows"))'.dependencies]
 windows-sys = { version = "0.52", features = ["Win32_Foundation", "Win32_System_Threading"] }
 
@@ -176,6 +179,11 @@ libc = { version = "0.2.148", default-features = false }
 [build-dependencies]
 cc = { version = "1.0.83", default-features = false }
 
+# At least 1.0.93 is requried for visionOS, but some versions around that point
+# have bugs that seem to have been fixed in 1.0.97 or so.
+[target.'cfg(all(target_vendor = "apple", target_os = "visionos"))'.build-dependencies]
+cc = { version = "1.0.97", default-features = false }
+
 [features]
 # These features are documented in the top-level module's documentation.
 default = ["alloc", "dev_urandom_fallback"]
diff --git a/build.rs b/build.rs
index eb0a779671..e87e53dfff 100644
--- a/build.rs
+++ b/build.rs
@@ -190,12 +190,12 @@ const ASM_TARGETS: &[AsmTarget] = &[
         perlasm_format: "elf",
     },
     AsmTarget {
-        oss: MACOS_ABI,
+        oss: APPLE_ABI,
         arch: AARCH64,
         perlasm_format: "ios64",
     },
     AsmTarget {
-        oss: MACOS_ABI,
+        oss: APPLE_ABI,
         arch: X86_64,
         perlasm_format: "macosx",
     },
@@ -255,9 +255,8 @@ const NASM: &str = "nasm";
 
 /// Operating systems that have the same ABI as macOS on every architecture
 /// mentioned in `ASM_TARGETS`.
-const MACOS_ABI: &[&str] = &["ios", MACOS, "tvos"];
+const APPLE_ABI: &[&str] = &["ios", "macos", "tvos", "visionos", "watchos"];
 
-const MACOS: &str = "macos";
 const WINDOWS: &str = "windows";
 
 fn main() {
@@ -562,7 +561,7 @@ fn configure_cc(c: &mut cc::Build, target: &Target, c_root_dir: &Path, include_d
         let _ = c.flag(f);
     }
 
-    if target.os.as_str() == MACOS {
+    if APPLE_ABI.contains(&target.os.as_str()) {
         // ``-gfull`` is required for Darwin's |-dead_strip|.
         let _ = c.flag("-gfull");
     } else if !compiler.is_like_msvc() {
diff --git a/mk/install-build-tools.sh b/mk/install-build-tools.sh
index 81fd9ed1ba..ca7129c7b0 100755
--- a/mk/install-build-tools.sh
+++ b/mk/install-build-tools.sh
@@ -68,6 +68,11 @@ case ${target-} in
 esac
 
 case ${target-} in
+aarch64-apple-tvos | aarch64-apple-tvos-sim | \
+aarch64-apple-visionos | aarch64-apple-visionos-sim | \
+aarch64-apple-watchos | aarch64-apple-watchos-sim)
+  build_std=1
+  ;;
 aarch64-unknown-linux-gnu)
   # Clang is needed for code coverage.
   use_clang=1
@@ -214,8 +219,12 @@ esac
 
 rustup toolchain install --no-self-update --profile=minimal ${toolchain}
 if [ -n "${target-}" ]; then
-  rustup target add --toolchain=${toolchain} ${target}
+  if [ -n "${build_std-}" ]; then
+    rustup +${toolchain} component add rust-src
+  else
+    rustup +${toolchain} target add ${target}
+  fi
 fi
 if [ -n "${RING_COVERAGE-}" ]; then
-  rustup toolchain install --profile=minimal ${toolchain} --component llvm-tools-preview
+  rustup +${toolchain} component add llvm-tools-preview
 fi
diff --git a/src/cpu/arm.rs b/src/cpu/arm.rs
index be6322af6d..def58f9790 100644
--- a/src/cpu/arm.rs
+++ b/src/cpu/arm.rs
@@ -40,7 +40,7 @@ mod abi_assumptions {
 
 cfg_if::cfg_if! {
     if #[cfg(all(target_arch = "aarch64",
-                 any(target_os = "ios", target_os = "macos", target_os = "tvos")))] {
+                 any(target_os = "ios", target_os = "macos", target_os = "tvos", target_os = "visionos", target_os = "watchos")))] {
         mod darwin;
         use darwin as detect;
     } else if #[cfg(all(target_arch = "aarch64", target_os = "fuchsia"))] {
diff --git a/src/ec/curve25519/x25519.rs b/src/ec/curve25519/x25519.rs
index 60eaa8afc1..4326752cd3 100644
--- a/src/ec/curve25519/x25519.rs
+++ b/src/ec/curve25519/x25519.rs
@@ -62,7 +62,7 @@ fn x25519_public_from_private(
     let private_key: &[u8; SCALAR_LEN] = private_key.bytes_less_safe().try_into()?;
     let private_key = ops::MaskedScalar::from_bytes_masked(*private_key);
 
-    #[cfg(all(not(target_os = "ios"), target_arch = "arm"))]
+    #[cfg(all(not(target_vendor = "apple"), target_arch = "arm"))]
     {
         if cpu::arm::NEON.available(cpu_features) {
             static MONTGOMERY_BASE_POINT: [u8; 32] = [
@@ -108,7 +108,7 @@ fn x25519_ecdh(
         point: &ops::EncodedPoint,
         #[allow(unused_variables)] cpu_features: cpu::Features,
     ) {
-        #[cfg(all(not(target_os = "ios"), target_arch = "arm"))]
+        #[cfg(all(not(target_vendor = "apple"), target_arch = "arm"))]
         {
             if cpu::arm::NEON.available(cpu_features) {
                 return x25519_neon(out, scalar, point);
@@ -157,7 +157,7 @@ fn x25519_ecdh(
     Ok(())
 }
 
-#[cfg(all(not(target_os = "ios"), target_arch = "arm"))]
+#[cfg(all(not(target_vendor = "apple"), target_arch = "arm"))]
 fn x25519_neon(out: &mut ops::EncodedPoint, scalar: &ops::MaskedScalar, point: &ops::EncodedPoint) {
     prefixed_extern! {
         fn x25519_NEON(
diff --git a/src/polyfill/cstr.rs b/src/polyfill/cstr.rs
index 74c0176fdb..4c411d3300 100644
--- a/src/polyfill/cstr.rs
+++ b/src/polyfill/cstr.rs
@@ -12,6 +12,17 @@
 // OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN
 // CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
 
+#![cfg(all(
+    target_vendor = "apple",
+    any(
+        target_os = "ios",
+        target_os = "macos",
+        target_os = "tvos",
+        target_os = "visionos",
+        target_os = "watchos"
+    )
+))]
+
 //! Work around lack of `core::ffi::CStr` prior to Rust 1.64, and the lack of
 //! `const fn` support for `CStr` in later versions.
 
diff --git a/src/rand.rs b/src/rand.rs
index 0d55635a00..71ba60288b 100644
--- a/src/rand.rs
+++ b/src/rand.rs
@@ -132,16 +132,23 @@ impl crate::sealed::Sealed for SystemRandom {}
     target_os = "hermit",
     target_os = "hurd",
     target_os = "illumos",
-    target_os = "ios",
     target_os = "linux",
-    target_os = "macos",
     target_os = "netbsd",
     target_os = "openbsd",
     target_os = "redox",
     target_os = "solaris",
-    target_os = "tvos",
     target_os = "vita",
     target_os = "windows",
+    all(
+        target_vendor = "apple",
+        any(
+            target_os = "ios",
+            target_os = "macos",
+            target_os = "tvos",
+            target_os = "visionos",
+            target_os = "watchos",
+        )
+    ),
     all(
         target_arch = "wasm32",
         any(