diff --git a/.github/workflows/build-mgrs.yml b/.github/workflows/build-mgrs.yml
new file mode 100644
index 000000000..1b57256d9
--- /dev/null
+++ b/.github/workflows/build-mgrs.yml
@@ -0,0 +1,80 @@
+# SPDX-FileCopyrightText: 2026 The RISE Project
+# SPDX-License-Identifier: MIT
+---
+# This workflow is based on: https://github.com/hobuinc/mgrs/blob/1.5.4/.github/workflows/deploy.yml
+name: Build mgrs wheels (riscv64)
+
+on:
+  workflow_dispatch:
+    inputs:
+      version:
+        description: 'mgrs version to build (git tag, e.g. 1.5.4)'
+        required: true
+        default: '1.5.4'
+  pull_request:
+    paths:
+      - '.github/workflows/build-mgrs.yml'
+
+concurrency:
+  group: ${{ github.workflow }}-${{ inputs.version || '1.5.4' }}-${{ github.head_ref || github.run_id }}
+  cancel-in-progress: true
+
+permissions:
+  contents: read  # to fetch code (actions/checkout)
+
+env:
+  # `inputs.version` is empty on pull_request events; default to 1.5.4 there.
+  MGRS_VERSION: ${{ inputs.version || '1.5.4' }}
+  MANYLINUX_RISCV64_IMAGE: quay.io/pypa/manylinux_2_39_riscv64
+
+jobs:
+  setup:
+    uses: $/.github/workflows/_setup.yml
+
+  build_wheels:
+    needs: [setup]
+    name: Build mgrs ${{ inputs.version || '1.5.4' }} ${{ matrix.python }}-manylinux_riscv64
+    runs-on: ubuntu-24.04-riscv
+    timeout-minutes: 60
+    strategy:
+      fail-fast: false
+      matrix:
+        python: ["cp312", "cp313", "cp314", "cp314t"]
+
+    steps:
+      - name: Checkout mgrs ${{ env.MGRS_VERSION }}
+        uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
+        with:
+          repository: hobuinc/mgrs
+          ref: ${{ env.MGRS_VERSION }}
+          persist-credentials: false
+
+      - uses: pypa/cibuildwheel@1828c10ab37f080699c7b81cea34097c684a7074  # v4.2.0
+        with:
+          output-dir: wheelhouse/
+          only: ${{ matrix.python }}-manylinux_riscv64
+        env:
+          CIBW_MANYLINUX_RISCV64_IMAGE: ${{ env.MANYLINUX_RISCV64_IMAGE }}
+          # Upstream ships this commented out; tests/test.txt is a doctest that
+          # pytest's default --doctest-glob (test*.txt) already picks up.
+          CIBW_TEST_REQUIRES: pytest
+          # Stage only tests/, not the checkout's own mgrs/ package, or `import mgrs`
+          # in the doctest resolves to the checkout instead of the installed wheel.
+          CIBW_TEST_SOURCES: tests
+          CIBW_TEST_COMMAND: pytest tests
+
+      - uses: actions/upload-artifact@043fb46d1a93c77aae656e7c1c64a875d1fc6a0a  # v7.0.1
+        with:
+          name: mgrs-${{ env.MGRS_VERSION }}-${{ matrix.python }}-manylinux_riscv64
+          path: wheelhouse/*.whl
+          if-no-files-found: error
+
+  publish:
+    name: Publish mgrs ${{ inputs.version || '1.5.4' }}
+    needs: [setup, build_wheels]
+    permissions:
+      contents: write
+      pull-requests: write
+    uses: $/.github/workflows/_publish-wheel.yml
+    with:
+      artifact-pattern: mgrs-${{ inputs.version || '1.5.4' }}-*-manylinux_riscv64