diff --git a/coin/provisioning/common/windows/zlib-helpers.ps1 b/coin/provisioning/common/windows/zlib-helpers.ps1
new file mode 100644
index 00000000..ea3a9ba6
--- /dev/null
+++ b/coin/provisioning/common/windows/zlib-helpers.ps1
@@ -0,0 +1,80 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+. "$PSScriptRoot\helpers.ps1"
+
+function CpuArchToString {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $Architecture
+    )
+
+    $arhitecture = switch ($Architecture) {
+        ([CpuArch]::arm64) {
+            'arm64'
+        }
+        ([CpuArch]::x64) {
+            'amd64'
+        }
+        default {
+            throw "Unsupported architecture: '$Architecture'"
+        }
+    }
+
+    return $arhitecture
+}
+
+function StringToCpuArch {
+    param (
+        [Parameter(Mandatory)]
+        [string] $Architecture
+    )
+
+    $arhitecture = switch ($Architecture) {
+        'arm64' {
+            [CpuArch]::arm64
+        }
+        'amd64' {
+            [CpuArch]::x64
+        }
+        default {
+            throw "Unsupported architecture: '$Architecture'"
+        }
+    }
+
+    return $arhitecture
+}
+
+function GetZlibEnvironmentVariableName {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture
+    )
+
+    $architecture  = CpuArchToString -Architecture $TargetArchitecture
+    $environmentVariableName = "ZLIB_PATH_$architecture".ToUpper()
+
+    return $environmentVariableName
+}
+
+function GetZlibPathByCpuArch {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture
+    )
+
+    $environmentVariableName = GetZlibEnvironmentVariableName -TargetArchitecture $TargetArchitecture
+
+    return [System.Environment]::GetEnvironmentVariable($environmentVariableName, [System.EnvironmentVariableTarget]::Machine)
+}
+
+function GetZlibPathByString {
+    param (
+        [Parameter(Mandatory)]
+        [string] $TargetArchitecture
+    )
+
+    $targetArchitecture = StringToCpuArch -Architecture $TargetArchitecture
+
+    return GetZlibPathByCpuArch -TargetArchitecture $targetArchitecture
+}
diff --git a/coin/provisioning/common/windows/zlib.ps1 b/coin/provisioning/common/windows/zlib.ps1
new file mode 100644
index 00000000..f725f8f6
--- /dev/null
+++ b/coin/provisioning/common/windows/zlib.ps1
@@ -0,0 +1,204 @@
+# Copyright (C) 2025 The Qt Company Ltd.
+# SPDX-License-Identifier: LicenseRef-Qt-Commercial OR LGPL-3.0-only OR GPL-2.0-only OR GPL-3.0-only
+
+# This script performs manual copying and patching of the zlib source to support
+# multi-architecture builds on Windows using Microsoft's nmake and Makefile.msc.
+#
+# Reasons for this approach:
+#
+# 1. In-source build system:
+#    zlib's build system (Makefile.msc) writes all build artifacts directly into the source
+#    directory. To allow concurrent builds for different architectures (e.g., x64 and arm64),
+#    we copy the relevant source files into per-architecture build directories to isolate artifacts.
+#
+# 2. Incompatible linker base address:
+#    The default Makefile.msc contains a hardcoded image base address ('-base:0x5A4C0000') for the
+#    linker. This is invalid for ARM64 targets, which require base addresses above 4 GB. The script
+#    patches this line out to prevent linker errors.
+#
+# 3. Broken #include in zconf.h:
+#    Based on FFmpeg documentation (https://ffmpeg.org/platform.html#Microsoft-Visual-C_002b_002b-or-Intel-C_002b_002b-Compiler-for-Windows),
+#    zconf.h may erroneously include '<unistd.h>', which doesn't exist on Windows. While Visual Studio 2022
+#    builds tolerate this, we patch it out to ensure compatibility with older toolchains.
+#
+# These workarounds allow us to run reproducible, architecture-specific builds in CI without modifying
+# the original source tree or requiring upstream changes.
+
+. "$PSScriptRoot\helpers.ps1"
+. "$PSScriptRoot\zlib-helpers.ps1"
+
+$VERSION='1.3.1'
+$SHA1='f535367b1a11e2f9ac3bec723fb007fbc0d189e5'
+
+$WIN32_DIRECTORY='win32'
+$MAKEFILE="$WIN32_DIRECTORY\Makefile.msc"
+
+function BuildZlib {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $HostArchitecture,
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture
+    )
+
+    PrepareBuildEnvironment -HostArchitecture $HostArchitecture -TargetArchitecture $TargetArchitecture
+
+    nmake /f $MAKEFILE
+}
+
+function CopySource {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture
+    )
+
+    $testDirectory='test'
+
+    $buildDirectory = GetBuildDirectory -TargetArchitecture $TargetArchitecture
+    $win32BuildDirectory = "$buildDirectory\$WIN32_DIRECTORY"
+    $testBuildDirectory = "$buildDirectory\$testDirectory"
+
+    New-Item -Path $buildDirectory -ItemType 'Directory'
+    New-Item -Path $win32BuildDirectory -ItemType 'Directory'
+    New-Item -Path $testBuildDirectory -ItemType 'Directory'
+
+    Copy-Item '*' -Include '*.c','*.h' -Destination $buildDirectory
+    Copy-Item "$WIN32_DIRECTORY\*" -Include '*.def','*.msc','*.rc' -Destination $win32BuildDirectory
+    Copy-Item "$testDirectory\*" -Include '*.c' -Destination $testBuildDirectory
+}
+
+function GetBuildDirectory {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture
+    )
+
+    $architectureDirectory  = CpuArchToString -Architecture $TargetArchitecture
+
+    return "build\$architectureDirectory"
+}
+
+function GetSource {
+    $unzipDirectory = "C:\"
+    $zlibName="zlib-$VERSION"
+
+    $zlibDirectory = "$unzipDirectory$zlibName"
+
+    $urlCached="http://ci-files01-hki.ci.qt.io/input/zlib/zlib-$VERSION.tar.gz"
+    $urlPublic="https://github.com/madler/zlib/releases/download/v$VERSION/zlib-$VERSION.tar.gz"
+
+    $downloadPath = "C:\Windows\Temp\$zlibName.tar.gz"
+
+    Write-Host "Fetching zlib $VERSION..."
+
+    Download $urlPublic $urlCached $downloadPath
+    Verify-Checksum $downloadPath $SHA1
+    Extract-tar_gz $downloadPath $unzipDirectory
+    Remove $downloadPath
+
+    return $zlibDirectory
+}
+
+function GetTargetArchitectures {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $HostArchitecture
+    )
+
+    $targetArhitectures = @([CpuArch]::arm64)
+
+    if ($HostArchitecture -eq [CpuArch]::x64) {
+        $targetArhitectures += [CpuArch]::x64
+    }
+
+    return $targetArhitectures
+}
+
+function PatchMakefile {
+    $pattern = '-base:\s*0x[0-9A-Fa-f]+'
+
+    (Get-Content $MAKEFILE) | ForEach-Object {
+        $_ -replace $pattern, ''
+    } | Set-Content $MAKEFILE
+}
+
+function PatchSource {
+    PatchZconf
+    PatchMakefile
+}
+
+function PatchZconf {
+    $zconf = 'zconf.h'
+    $pattern = '#\s*include\s*<unistd\.h>'
+
+    (Get-Content $zconf) | Where-Object {
+        $_ -notmatch $pattern
+    } | Set-Content $zconf
+}
+
+function PrepareBuild {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture
+    )
+
+    CopySource -TargetArchitecture $TargetArchitecture
+}
+
+function PrepareBuildEnvironment {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $HostArchitecture,
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture
+    )
+
+    $hostArhitecture = CpuArchToString -Architecture $HostArchitecture
+    $targetArhitecture = CpuArchToString -Architecture $TargetArchitecture
+
+    if (-not $(EnterVSDevShell -HostArch $hostArhitecture -Arch $targetArhitecture)) {
+        throw "Failed to prepare build environment for ${hostArhitecture}_${targetArhitecture}"
+    }
+}
+
+function SetZlibEnvironmentVariable {
+    param (
+        [Parameter(Mandatory)]
+        [CpuArch] $TargetArchitecture,
+        [Parameter(Mandatory)]
+        [string] $ZlibDirectory
+    )
+
+    $buildDirectory = GetBuildDirectory -TargetArchitecture $TargetArchitecture
+    $environmentVariableName = GetZlibEnvironmentVariableName -TargetArchitecture $TargetArchitecture
+    $environmentVariableValue = "$ZlibDirectory\$buildDirectory"
+
+    Set-EnvironmentVariable $environmentVariableName $environmentVariableValue
+}
+
+$zlibDirectory = GetSource
+$hostArchitecture = Get-CpuArchitecture
+$targetArchitectures = GetTargetArchitectures -HostArchitecture $hostArchitecture
+
+Push-Location $zlibDirectory
+
+try {
+    foreach ($targetArchitecture in $targetArchitectures) {
+        PrepareBuild -TargetArchitecture $targetArchitecture
+
+        $buildDirectory = GetBuildDirectory -TargetArchitecture $targetArchitecture
+        Push-Location $buildDirectory
+
+        try {
+            PatchSource
+            BuildZlib -HostArchitecture $hostArchitecture -TargetArchitecture $targetArchitecture
+            SetZlibEnvironmentVariable -TargetArchitecture $targetArchitecture -ZlibDirectory $zlibDirectory
+        }
+        finally {
+            Pop-Location
+        }
+    }
+}
+finally {
+    Pop-Location
+}
diff --git a/coin/provisioning/qtci-windows-10-x86_64/89-zlib.ps1 b/coin/provisioning/qtci-windows-10-x86_64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-10-x86_64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-10_21H2-x86_64/89-zlib.ps1 b/coin/provisioning/qtci-windows-10_21H2-x86_64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-10_21H2-x86_64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-10_22H2-x86_64/89-zlib.ps1 b/coin/provisioning/qtci-windows-10_22H2-x86_64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-10_22H2-x86_64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-11_21H2-x86_64/89-zlib.ps1 b/coin/provisioning/qtci-windows-11_21H2-x86_64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-11_21H2-x86_64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-11_22H2-aarch64/89-zlib.ps1 b/coin/provisioning/qtci-windows-11_22H2-aarch64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-11_22H2-aarch64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-11_22H2-x86_64/89-zlib.ps1 b/coin/provisioning/qtci-windows-11_22H2-x86_64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-11_22H2-x86_64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-11_23H2-aarch64/89-zlib.ps1 b/coin/provisioning/qtci-windows-11_23H2-aarch64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-11_23H2-aarch64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-11_23H2-x86_64/89-zlib.ps1 b/coin/provisioning/qtci-windows-11_23H2-x86_64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-11_23H2-x86_64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"
diff --git a/coin/provisioning/qtci-windows-11_24H2-x86_64/89-zlib.ps1 b/coin/provisioning/qtci-windows-11_24H2-x86_64/89-zlib.ps1
new file mode 100644
index 00000000..90751c34
--- /dev/null
+++ b/coin/provisioning/qtci-windows-11_24H2-x86_64/89-zlib.ps1
@@ -0,0 +1 @@
+. "$PSScriptRoot\..\common\windows\zlib.ps1"