diff --git a/automation/build/ubuntu/16.04-x86_64.dockerfile b/automation/build/ubuntu/16.04-x86_64.dockerfile
deleted file mode 100644
index 72a46389fa..0000000000
--- a/automation/build/ubuntu/16.04-x86_64.dockerfile
+++ /dev/null
@@ -1,65 +0,0 @@
-# syntax=docker/dockerfile:1
-FROM --platform=linux/amd64 ubuntu:16.04
-LABEL maintainer.name="The Xen Project"
-LABEL maintainer.email="xen-devel@lists.xenproject.org"
-
-ENV DEBIAN_FRONTEND=noninteractive
-
-RUN <<EOF
-#!/bin/bash
-    set -e
-
-    useradd --create-home user
-
-    apt-get update
-
-    DEPS=(
-        # Xen
-        bison
-        build-essential
-        checkpolicy
-        clang
-        flex
-        python3-minimal
-
-        # Tools (general)
-        ca-certificates
-        cpio
-        git-core
-        gzip
-        patch
-        perl
-        pkg-config
-        wget
-        # libxenguest dombuilder
-        libbz2-dev
-        libzstd-dev
-        liblzo2-dev
-        liblzma-dev
-        zlib1g-dev
-        # libacpi
-        acpica-tools
-        # libxl
-        uuid-dev
-        libyajl-dev
-        # RomBIOS
-        bcc
-        bin86
-        # xentop
-        libncurses5-dev
-        # Python bindings
-        python3-dev
-        # Ocaml bindings/oxenstored
-        ocaml-nox
-        ocaml-findlib
-
-        # Stubdom download/extract
-        bzip2
-    )
-
-    apt-get -y --no-install-recommends install "${DEPS[@]}"
-    rm -rf /var/lib/apt/lists/*
-EOF
-
-USER user
-WORKDIR /build
diff --git a/automation/gitlab-ci/build.yaml b/automation/gitlab-ci/build.yaml
index 0e5fb26c85..5a933e42f1 100644
--- a/automation/gitlab-ci/build.yaml
+++ b/automation/gitlab-ci/build.yaml
@@ -617,21 +617,16 @@ fedora-41-x86_64-gcc-debug:
   variables:
     CONTAINER: fedora:41-x86_64
 
-ubuntu-16.04-x86_64-gcc:
-  extends: .gcc-x86-64-build
-  variables:
-    CONTAINER: ubuntu:16.04-x86_64
-
-ubuntu-16.04-x86_64-gcc-debug:
-  extends: .gcc-x86-64-build-debug
-  variables:
-    CONTAINER: ubuntu:16.04-x86_64
-
 ubuntu-18.04-x86_64-gcc:
   extends: .gcc-x86-64-build
   variables:
     CONTAINER: ubuntu:18.04-x86_64
 
+ubuntu-18.04-x86_64-gcc-debug:
+  extends: .gcc-x86-64-build-debug
+  variables:
+    CONTAINER: ubuntu:18.04-x86_64
+
 ubuntu-20.04-x86_64-gcc:
   extends: .gcc-x86-64-build
   variables: