diff --git a/.github/workflows/docs.yaml b/.github/workflows/docs.yaml
index fe3212f82a7..434dcbb6c77 100644
--- a/.github/workflows/docs.yaml
+++ b/.github/workflows/docs.yaml
@@ -85,33 +85,3 @@ jobs:
           github_token: ${{ secrets.GITHUB_TOKEN }}
           publish_dir: ./book
           destination_dir: ./${{ needs.pre.outputs.branch-version }}
-
-################################################################################
-  pages-devdocs:
-    name: GitHub Pages (developer docs)
-    runs-on: ubuntu-latest
-    needs:
-      - pre
-    steps:
-      - uses: actions/checkout@v4
-
-      - name: "Set up Sphinx"
-        uses: matrix-org/setup-python-poetry@v1
-        with:
-          python-version: "3.x"
-          poetry-version: "1.3.2"
-          groups: "dev-docs"
-          extras: ""
-
-      - name: Build the documentation
-        run: |
-          cd dev-docs
-          poetry run make html
-
-      # Deploy to the target directory.
-      - name: Deploy to gh pages
-        uses: peaceiris/actions-gh-pages@4f9cc6602d3f66b9c108549d475ec49e8ef4d45e # v4.0.0
-        with:
-          github_token: ${{ secrets.GITHUB_TOKEN }}
-          publish_dir: ./dev-docs/_build/html
-          destination_dir: ./dev-docs/${{ needs.pre.outputs.branch-version }}
diff --git a/changelog.d/17073.doc b/changelog.d/17073.doc
new file mode 100644
index 00000000000..bc33887efec
--- /dev/null
+++ b/changelog.d/17073.doc
@@ -0,0 +1 @@
+Remove broken sphinx docs.
diff --git a/dev-docs/Makefile b/dev-docs/Makefile
deleted file mode 100644
index d4bb2cbb9ed..00000000000
--- a/dev-docs/Makefile
+++ /dev/null
@@ -1,20 +0,0 @@
-# Minimal makefile for Sphinx documentation
-#
-
-# You can set these variables from the command line, and also
-# from the environment for the first two.
-SPHINXOPTS    ?=
-SPHINXBUILD   ?= sphinx-build
-SOURCEDIR     = .
-BUILDDIR      = _build
-
-# Put it first so that "make" without argument is like "make help".
-help:
-	@$(SPHINXBUILD) -M help "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
-
-.PHONY: help Makefile
-
-# Catch-all target: route all unknown targets to Sphinx using the new
-# "make mode" option.  $(O) is meant as a shortcut for $(SPHINXOPTS).
-%: Makefile
-	@$(SPHINXBUILD) -M $@ "$(SOURCEDIR)" "$(BUILDDIR)" $(SPHINXOPTS) $(O)
diff --git a/dev-docs/conf.py b/dev-docs/conf.py
deleted file mode 100644
index 826d578c0be..00000000000
--- a/dev-docs/conf.py
+++ /dev/null
@@ -1,50 +0,0 @@
-# Configuration file for the Sphinx documentation builder.
-#
-# For the full list of built-in configuration values, see the documentation:
-# https://www.sphinx-doc.org/en/master/usage/configuration.html
-
-# -- Project information -----------------------------------------------------
-# https://www.sphinx-doc.org/en/master/usage/configuration.html#project-information
-
-project = "Synapse development"
-copyright = "2023, The Matrix.org Foundation C.I.C."
-author = "The Synapse Maintainers and Community"
-
-# -- General configuration ---------------------------------------------------
-# https://www.sphinx-doc.org/en/master/usage/configuration.html#general-configuration
-
-extensions = [
-    "autodoc2",
-    "myst_parser",
-]
-
-templates_path = ["_templates"]
-exclude_patterns = ["_build", "Thumbs.db", ".DS_Store"]
-
-
-# -- Options for Autodoc2 ----------------------------------------------------
-
-autodoc2_docstring_parser_regexes = [
-    # this will render all docstrings as 'MyST' Markdown
-    (r".*", "myst"),
-]
-
-autodoc2_packages = [
-    {
-        "path": "../synapse",
-        # Don't render documentation for everything as a matter of course
-        "auto_mode": False,
-    },
-]
-
-
-# -- Options for MyST (Markdown) ---------------------------------------------
-
-# myst_heading_anchors = 2
-
-
-# -- Options for HTML output -------------------------------------------------
-# https://www.sphinx-doc.org/en/master/usage/configuration.html#options-for-html-output
-
-html_theme = "furo"
-html_static_path = ["_static"]
diff --git a/dev-docs/index.rst b/dev-docs/index.rst
deleted file mode 100644
index 1ef210460ab..00000000000
--- a/dev-docs/index.rst
+++ /dev/null
@@ -1,22 +0,0 @@
-.. Synapse Developer Documentation documentation master file, created by
-   sphinx-quickstart on Mon Mar 13 08:59:51 2023.
-   You can adapt this file completely to your liking, but it should at least
-   contain the root `toctree` directive.
-
-Welcome to the Synapse Developer Documentation!
-===========================================================
-
-.. toctree::
-   :maxdepth: 2
-   :caption: Contents:
-
-   modules/federation_sender
-
-
-
-Indices and tables
-==================
-
-* :ref:`genindex`
-* :ref:`modindex`
-* :ref:`search`
diff --git a/dev-docs/modules/federation_sender.md b/dev-docs/modules/federation_sender.md
deleted file mode 100644
index dac6852c166..00000000000
--- a/dev-docs/modules/federation_sender.md
+++ /dev/null
@@ -1,5 +0,0 @@
-Federation Sender
-=================
-
-```{autodoc2-docstring} synapse.federation.sender
-```
diff --git a/pyproject.toml b/pyproject.toml
index 150084a75eb..9ad674b603b 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -364,17 +364,6 @@ towncrier = ">=18.6.0rc1"
 tomli = ">=1.2.3"
 
 
-# Dependencies for building the development documentation
-[tool.poetry.group.dev-docs]
-optional = true
-
-[tool.poetry.group.dev-docs.dependencies]
-sphinx = {version = "^6.1", python = "^3.8"}
-sphinx-autodoc2 = {version = ">=0.4.2,<0.6.0", python = "^3.8"}
-myst-parser = {version = "^1.0.0", python = "^3.8"}
-furo = ">=2022.12.7,<2025.0.0"
-
-
 [build-system]
 # The upper bounds here are defensive, intended to prevent situations like
 # https://github.com/matrix-org/synapse/issues/13849 and