diff --git a/.github/workflows/build-linux.yml b/.github/workflows/build-linux.yml
index 7b13b6646..fa2425e4d 100644
--- a/.github/workflows/build-linux.yml
+++ b/.github/workflows/build-linux.yml
@@ -20,26 +20,26 @@ jobs:
         # Github Actions requires a single row to be added to the build matrix.
         # See https://help.github.com/en/articles/workflow-syntax-for-github-actions.
         name: [
-          ubuntu-18.04-gcc-5,
-          ubuntu-18.04-gcc-9,
-          ubuntu-18.04-clang-9,
+          ubuntu-20.04-gcc-7,
+          ubuntu-20.04-gcc-9,
+          ubuntu-20.04-clang-9,
         ]
 
         build_type: [Debug, Release]
         build_unstable: [ON]
         include:
-          - name: ubuntu-18.04-gcc-5
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-gcc-7
+            os: ubuntu-20.04
             compiler: gcc
-            version: "5"
+            version: "7"
 
-          - name: ubuntu-18.04-gcc-9
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-gcc-9
+            os: ubuntu-20.04
             compiler: gcc
             version: "9"
 
-          - name: ubuntu-18.04-clang-9
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-clang-9
+            os: ubuntu-20.04
             compiler: clang
             version: "9"
 
@@ -60,9 +60,9 @@ jobs:
             gpg -a --export $LLVM_KEY | sudo apt-key add -
             sudo add-apt-repository "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main"
           fi
-          sudo apt-get -y update
 
-          sudo apt-get -y install cmake build-essential pkg-config libpython-dev python-numpy libicu-dev
+          sudo apt-get -y update
+          sudo apt-get -y install cmake build-essential pkg-config libpython3-dev python3-numpy libicu-dev
 
           if [ "${{ matrix.compiler }}" = "gcc" ]; then
             sudo apt-get install -y g++-${{ matrix.version }} g++-${{ matrix.version }}-multilib
diff --git a/.github/workflows/build-python.yml b/.github/workflows/build-python.yml
index 1e1519da6..4eb861ecc 100644
--- a/.github/workflows/build-python.yml
+++ b/.github/workflows/build-python.yml
@@ -19,34 +19,34 @@ jobs:
         # Github Actions requires a single row to be added to the build matrix.
         # See https://help.github.com/en/articles/workflow-syntax-for-github-actions.
         name: [
-          ubuntu-18.04-gcc-5,
-          ubuntu-18.04-gcc-9,
-          ubuntu-18.04-clang-9,
+          ubuntu-20.04-gcc-7,
+          ubuntu-20.04-gcc-9,
+          ubuntu-20.04-clang-9,
           macOS-11-xcode-13.4.1,
-          ubuntu-18.04-gcc-5-tbb,
+          ubuntu-20.04-gcc-7-tbb,
         ]
 
         build_type: [Debug, Release]
         python_version: [3]
         include:
-          - name: ubuntu-18.04-gcc-5
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-gcc-7
+            os: ubuntu-20.04
             compiler: gcc
-            version: "5"
+            version: "7"
 
-          - name: ubuntu-18.04-gcc-9
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-gcc-9
+            os: ubuntu-20.04
             compiler: gcc
             version: "9"
 
-          - name: ubuntu-18.04-clang-9
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-clang-9
+            os: ubuntu-20.04
             compiler: clang
             version: "9"
 
           # NOTE temporarily added this as it is a required check.
-          - name: ubuntu-18.04-clang-9
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-clang-9
+            os: ubuntu-20.04
             compiler: clang
             version: "9"
             build_type: Debug
@@ -57,10 +57,10 @@ jobs:
             compiler: xcode
             version: "13.4.1"
 
-          - name: ubuntu-18.04-gcc-5-tbb
-            os: ubuntu-18.04
+          - name: ubuntu-20.04-gcc-7-tbb
+            os: ubuntu-20.04
             compiler: gcc
-            version: "5"
+            version: "7"
             flag: tbb
 
     steps:
@@ -79,9 +79,9 @@ jobs:
             gpg -a --export $LLVM_KEY | sudo apt-key add -
             sudo add-apt-repository "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main"
           fi
+
           sudo apt-get -y update
-          
-          sudo apt-get -y install cmake build-essential pkg-config libpython-dev python-numpy libboost-all-dev
+          sudo apt-get -y install cmake build-essential pkg-config libpython3-dev python3-numpy libboost-all-dev
           
           if [ "${{ matrix.compiler }}" = "gcc" ]; then
             sudo apt-get install -y g++-${{ matrix.version }} g++-${{ matrix.version }}-multilib
diff --git a/.github/workflows/build-special.yml b/.github/workflows/build-special.yml
index d357b9a34..ef7d7723d 100644
--- a/.github/workflows/build-special.yml
+++ b/.github/workflows/build-special.yml
@@ -32,31 +32,31 @@ jobs:
 
         include:
           - name: ubuntu-gcc-deprecated
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             compiler: gcc
             version: "9"
             flag: deprecated
 
           - name: ubuntu-gcc-quaternions
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             compiler: gcc
             version: "9"
             flag: quaternions
 
           - name: ubuntu-gcc-tbb
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             compiler: gcc
             version: "9"
             flag: tbb
 
           - name: ubuntu-cayleymap
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             compiler: gcc
             version: "9"
             flag: cayley
 
           - name: ubuntu-system-libs
-            os: ubuntu-18.04
+            os: ubuntu-20.04
             compiler: gcc
             version: "9"
             flag: system-libs
@@ -74,9 +74,9 @@ jobs:
             gpg -a --export 15CF4D18AF4F7421 | sudo apt-key add -
             sudo add-apt-repository "deb http://apt.llvm.org/bionic/ llvm-toolchain-bionic-9 main"
           fi
-          sudo apt-get -y update
 
-          sudo apt-get -y install cmake build-essential pkg-config libpython-dev python-numpy libicu-dev
+          sudo apt-get -y update
+          sudo apt-get -y install cmake build-essential pkg-config libpython3-dev python3-numpy libicu-dev
 
           if [ "${{ matrix.compiler }}" = "gcc" ]; then
             sudo apt-get install -y g++-${{ matrix.version }} g++-${{ matrix.version }}-multilib