diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6685cb92c2..b5f606694d 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -13,17 +13,8 @@ jobs:
     strategy:
       matrix:
         include:
-          - elixir: 1.11.4
-            otp: 24.3
-
-          - elixir: 1.12.3
-            otp: 24.3
-
-          - elixir: 1.14.5
-            otp: 25.3.2.9
-
-          - elixir: 1.15.x
-            otp: 25.x
+          - elixir: 1.15.8
+            otp: 24.3.4.17
 
           - elixir: 1.17.3
             otp: 27.2
@@ -33,43 +24,43 @@ jobs:
     runs-on: ubuntu-20.04
 
     steps:
-    - name: Checkout
-      uses: actions/checkout@v4
-
-    - name: Set up Elixir
-      uses: erlef/setup-beam@v1
-      with:
-        elixir-version: ${{ matrix.elixir }}
-        otp-version: ${{ matrix.otp }}
-
-    - name: Restore deps and _build cache
-      uses: actions/cache@v4
-      with:
-        path: |
-          deps
-          _build
-        key: deps-${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-${{ hashFiles('**/mix.lock') }}
-        restore-keys: |
-          deps-${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}
-
-    - name: Install dependencies
-      run: mix deps.get --only test
-
-    - name: Remove compiled application files
-      run: mix clean
-
-    - name: Compile & lint dependencies
-      run: mix compile --warnings-as-errors
-      if: ${{ matrix.lint }}
-
-    - name: Run tests
-      run: mix test
-
-    - name: Run installer test
-      run: |
-        cd installer
-        mix test
-      if: ${{ matrix.installer }}
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Set up Elixir
+        uses: erlef/setup-beam@v1
+        with:
+          elixir-version: ${{ matrix.elixir }}
+          otp-version: ${{ matrix.otp }}
+
+      - name: Restore deps and _build cache
+        uses: actions/cache@v4
+        with:
+          path: |
+            deps
+            _build
+          key: deps-${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}-${{ hashFiles('**/mix.lock') }}
+          restore-keys: |
+            deps-${{ runner.os }}-${{ matrix.otp }}-${{ matrix.elixir }}
+
+      - name: Install dependencies
+        run: mix deps.get --only test
+
+      - name: Remove compiled application files
+        run: mix clean
+
+      - name: Compile & lint dependencies
+        run: mix compile --warnings-as-errors
+        if: ${{ matrix.lint }}
+
+      - name: Run tests
+        run: mix test
+
+      - name: Run installer test
+        run: |
+          cd installer
+          mix test
+        if: ${{ matrix.installer }}
 
   npm_test:
     name: npm test
diff --git a/lib/phoenix/code_reloader/server.ex b/lib/phoenix/code_reloader/server.ex
index 49169f97dc..66913c9154 100644
--- a/lib/phoenix/code_reloader/server.ex
+++ b/lib/phoenix/code_reloader/server.ex
@@ -182,15 +182,6 @@ defmodule Phoenix.CodeReloader.Server do
     end
   end
 
-  if Version.match?(System.version(), "< 1.15.0-dev") do
-    defp purge_protocols(path) do
-      purge_modules(path)
-      Code.delete_path(path)
-    end
-  else
-    defp purge_protocols(_path), do: :ok
-  end
-
   if Version.match?(System.version(), ">= 1.18.0-dev") do
     defp warn_missing_mix_listener do
       if Mix.Project.get() != Phoenix.MixProject do
@@ -226,11 +217,6 @@ defmodule Phoenix.CodeReloader.Server do
     config = Mix.Project.config()
     path = Mix.Project.consolidation_path(config)
 
-    # TODO: Remove this conditional when requiring Elixir v1.15+
-    if config[:consolidate_protocols] do
-      purge_protocols(path)
-    end
-
     mix_compile_deps(
       Mix.Dep.cached(),
       apps_to_reload,
@@ -364,7 +350,7 @@ defmodule Phoenix.CodeReloader.Server do
         exit({:shutdown, 1})
 
       result == :ok && config[:consolidate_protocols] ->
-        # TODO: Calling compile.protocols may no longer be required from Elixir v1.18
+        # TODO: Calling compile.protocols is no longer be required from Elixir v1.19
         Mix.Task.reenable("compile.protocols")
         Mix.Task.run("compile.protocols", [])
         :ok
diff --git a/lib/phoenix/router.ex b/lib/phoenix/router.ex
index 84b5afd793..35d869e0c3 100644
--- a/lib/phoenix/router.ex
+++ b/lib/phoenix/router.ex
@@ -523,15 +523,7 @@ defmodule Phoenix.Router do
       """
       def call(conn, _opts) do
         %{method: method, path_info: path_info, host: host} = conn = prepare(conn)
-
-        # TODO: Remove try/catch on Elixir v1.13 as decode no longer raises
-        decoded =
-          try do
-            Enum.map(path_info, &URI.decode/1)
-          rescue
-            ArgumentError ->
-              raise MalformedURIError, "malformed URI path: #{inspect(conn.request_path)}"
-          end
+        decoded = Enum.map(path_info, &URI.decode/1)
 
         case __match_route__(decoded, method, host) do
           {metadata, prepare, pipeline, plug_opts} ->
diff --git a/lib/phoenix/socket/pool_supervisor.ex b/lib/phoenix/socket/pool_supervisor.ex
index a3297867fc..80cb8b510f 100644
--- a/lib/phoenix/socket/pool_supervisor.ex
+++ b/lib/phoenix/socket/pool_supervisor.ex
@@ -45,7 +45,6 @@ defmodule Phoenix.Socket.PoolSupervisor do
 
   @impl true
   def init({endpoint, name, partitions}) do
-    # TODO: Use persistent term on Elixir v1.12+
     ref = :ets.new(name, [:public, read_concurrency: true])
     :ets.insert(ref, {:partitions, partitions})
     Phoenix.Config.permanent(endpoint, {:socket, name}, ref)
@@ -115,8 +114,7 @@ defmodule Phoenix.Socket.PoolDrainer do
     end
 
     for {pids, index} <-
-      collection |> Stream.concat() |> Stream.chunk_every(size) |> Stream.with_index(1) do
-
+          collection |> Stream.concat() |> Stream.chunk_every(size) |> Stream.with_index(1) do
       spawn(fn ->
         for pid <- pids do
           send(pid, %Phoenix.Socket.Broadcast{event: "phx_drain"})
diff --git a/mix.exs b/mix.exs
index 759e8076c4..d1a83cf1d1 100644
--- a/mix.exs
+++ b/mix.exs
@@ -14,7 +14,7 @@ defmodule Phoenix.MixProject do
   # If the elixir requirement is updated, we need to make the installer
   # use at least the minimum requirement used here. Although often the
   # installer is ahead of Phoenix itself.
-  @elixir_requirement "~> 1.11"
+  @elixir_requirement "~> 1.15"
 
   def project do
     [
@@ -86,9 +86,9 @@ defmodule Phoenix.MixProject do
       {:phoenix_template, "~> 1.0"},
       {:websock_adapter, "~> 0.5.3"},
 
-      # TODO drop phoenix_view as an optional dependency in Phoenix v2.0
+      # TODO Drop phoenix_view as an optional dependency in Phoenix v2.0
       {:phoenix_view, "~> 2.0", optional: true},
-      # TODO drop castore when we require OTP 25+
+      # TODO Drop castore when we require OTP 25+ / Elixir v1.17+
       {:castore, ">= 0.0.0"},
 
       # Optional deps