diff --git a/pyproject.toml b/pyproject.toml
index f87303460a..ef82f1fc50 100644
--- a/pyproject.toml
+++ b/pyproject.toml
@@ -76,6 +76,8 @@ LINKSTATIC = "1"
 # Standardize the install directory for libraries, as expected by
 # other parts of the wheels build process.
 CMAKE_INSTALL_LIBDIR = "lib"
+# Always build against zlib-ng (instead of regular zlib)
+DISABLE_ZLIB = "1"
 
 # Dynamically set the package version metadata by pasrsing CMakeLists.txt.
 [tool.scikit-build.metadata.version]
diff --git a/src/cmake/build_ZLIB.cmake b/src/cmake/build_ZLIB.cmake
index 6c08e92a33..220e161b12 100644
--- a/src/cmake/build_ZLIB.cmake
+++ b/src/cmake/build_ZLIB.cmake
@@ -3,19 +3,81 @@
 # https://github.com/AcademySoftwareFoundation/OpenImageIO
 
 ######################################################################
-# ZLIB by hand!
+# ZLIB / ZLIB-NG by hand!
 ######################################################################
 
-set_cache (ZLIB_BUILD_VERSION 1.3.1 "ZLIB version for local builds")
-set (ZLIB_GIT_REPOSITORY "https://github.com/madler/zlib")
-set (ZLIB_GIT_TAG "v${ZLIB_BUILD_VERSION}")
+# This script builds either zlib or zlib-ng (in compatibility mode) from source.
 
-set_cache (ZLIB_BUILD_SHARED_LIBS ${LOCAL_BUILD_SHARED_LIBS_DEFAULT}
-           DOC "Should execute a local ZLIB build, if necessary, build shared libraries" ADVANCED)
+# Zlib-ng is a fork of zlib that is actively maintained and has some
+# performance improvments over the original zlib which pertain to 
+# PNG and WebP plugin performance (on Windows, in particular).
+
+# By default, we build zlib-ng in zlib API compatibility mode. This 
+# allows OIIO and its dependencies to use zlib-ng v2.2.4 as a drop-in 
+# replacement for zlib v1.3.1. 
+
+# Please note -- this means that `find_package(ZLIB)` will recognize zlib-ng
+# as zlib, and set ZLIB_VERSION = "1.3.1" (instead of zlib-ng's version)
+
+
+# There are two ways to build against zlib instead of zlib-ng:
+
+#   1. At build time, set `ENABLE_ZLIBNG=OFF` to
+#      to build with the original zlib (defaults to ON).
+
+#   2. When using the `checked_find_package` macro, require a version
+#      less than 2.0.0, e.g. `find_package(ZLIB 1.3.1 REQUIRED)`.
+
+
+set (ZLIB_VERSION_LATEST    "1.3.1")
+set (ZLIBNG_VERSION_LATEST  "2.2.4")
+
+# By default, we build zlib-ng in compatibility mode. 
+# Set ENABLE_ZLIBNG=OFF to build the original zlib.
+check_is_enabled(ZLIBNG ENABLE_ZLIBNG)
+
+
+# Set the version to build; note that 1.x versions will build the original zlib,
+# while 2.x or later will build zlib-ng.
+if (ENABLE_ZLIBNG)
+    set_cache (ZLIB_BUILD_VERSION ${ZLIBNG_VERSION_LATEST} "ZLIB or ZLIB-NG version for local builds")
+else ()
+    set_cache (ZLIB_BUILD_VERSION ${ZLIB_VERSION_LATEST} "ZLIB or ZLIB-NG version for local builds")
+endif ()
+
+
+# Choose the git repository, tag format, and extra arguments based on version.
+# For now, we're assuming that the original zlib will never reach version 2.0, 
+# so anything greater than or equal to 2.0 is zlib-ng.
+if (ZLIB_BUILD_VERSION VERSION_LESS "2.0.0")
+  # Original zlib: use the 'v' prefix in the tag.
+  set (ZLIB_GIT_REPOSITORY "https://github.com/madler/zlib")
+  set (ZLIB_GIT_TAG "v${ZLIB_BUILD_VERSION}")
+  set (ZLIB_BUILD_OPTIONS "")
+  set (ZLIBNG_USED FALSE)
+  if (ENABLE_ZLIBNG)
+    message (STATUS "Building zlib version ${ZLIB_BUILD_VERSION}, even though ENABLE_ZLIBNG=${ENABLE_ZLIBNG}")
+    message (STATUS "If you believe this is a mistake, check usages of `checked_find_package(ZLIB ...)` in the code base.")
+    message (STATUS "See src/cmake/build_ZLIB.cmake for more details.")
+  else ()
+    message (STATUS "Building zlib version ${ZLIB_BUILD_VERSION}")
+  endif ()
+else ()
+  # zlib-ng: omit the 'v' prefix for the git tag and enable compatibility mode.
+  set (ZLIB_GIT_REPOSITORY "https://github.com/zlib-ng/zlib-ng")
+  set (ZLIB_GIT_TAG "${ZLIB_BUILD_VERSION}")
+  set (ZLIB_BUILD_OPTIONS "-DZLIB_COMPAT=ON;-DWITH_GTEST=OFF;-DWITH_GZFILEOP=OFF;-DZLIBNG_ENABLE_TESTS=OFF;-DZLIB_ENABLE_TESTS=OFF")
+  set (ZLIBNG_USED TRUE)
+  message (STATUS "Building zlib-ng version ${ZLIB_BUILD_VERSION}")
+endif ()
+
+
+set_cache (ZLIB_BUILD_SHARED_LIBS OFF
+  DOC "Should execute a local ZLIB build, if necessary, build shared libraries" ADVANCED)
 
 string (MAKE_C_IDENTIFIER ${ZLIB_BUILD_VERSION} ZLIB_VERSION_IDENT)
 
-build_dependency_with_cmake(ZLIB
+build_dependency_with_cmake (ZLIB
     VERSION         ${ZLIB_BUILD_VERSION}
     GIT_REPOSITORY  ${ZLIB_GIT_REPOSITORY}
     GIT_TAG         ${ZLIB_GIT_TAG}
@@ -26,16 +88,49 @@ build_dependency_with_cmake(ZLIB
         # Fix for zlib breaking against cmake 4.0.
         # Remove when zlib is fixed to declare its own minimum high enough.
         -D CMAKE_POLICY_VERSION_MINIMUM=3.5
+        ${ZLIB_BUILD_OPTIONS}
     )
 
 # Set some things up that we'll need for a subsequent find_package to work
 set (ZLIB_ROOT ${ZLIB_LOCAL_INSTALL_DIR})
 
-# Signal to caller that we need to find again at the installed location
-set (ZLIB_REFIND TRUE)
-set (ZLIB_VERSION ${ZLIB_BUILD_VERSION})
-set (ZLIB_REFIND_VERSION ${ZLIB_BUILD_VERSION})
 
-if (ZLIB_BUILD_SHARED_LIBS)
-    install_local_dependency_libs (ZLIB ZLIB)
+if (ZLIBNG_USED)
+    # zlib-ng provides a CMake config file, so we can use find_package directly.
+    find_package (ZLIB CONFIG REQUIRED HINTS ${ZLIB_LOCAL_INSTALL_DIR} NO_DEFAULT_PATH)
+
+    # First, locate the directory containing zlib.h.
+    find_path (ZLIB_INCLUDE_DIR
+        NAMES zlib.h
+        HINTS ${ZLIB_ROOT}/include
+    )
+
+    if (NOT ZLIB_INCLUDE_DIR)
+        message (FATAL_ERROR "Could not locate zlib-ng include directory.")
+    endif ()
+
+    message (STATUS "Found zlib-ng header directory: ${ZLIB_INCLUDE_DIR}")
+
+    # Read the contents of zlib.h
+    file (READ "${ZLIB_INCLUDE_DIR}/zlib.h" ZLIB_HEADER_CONTENT)
+
+    # Use a regular expression to search for the ZLIB_VERSION macro.
+    # This regex looks for a line like: #define ZLIB_VERSION "1.3.1.zlib-ng"
+    string (REGEX MATCH "#[ \t]*define[ \t]+ZLIB_VERSION[ \t]+\"([^\"]+)\"" _match "${ZLIB_HEADER_CONTENT}")
+
+    if (_match)
+    # The first capture group is stored in CMAKE_MATCH_1.
+        set (ZLIB_VERSION "${CMAKE_MATCH_1}")
+    endif ()
+    
+
+else ()
+    # Vanilla ZLIB doesn't ship with a CMake config file, so we'll just "refind" it with the
+    # usual arguments.
+    set (ZLIB_REFIND TRUE)
+    set (ZLIB_REFIND_VERSION ${ZLIB_BUILD_VERSION})
 endif ()
+
+if (ZLIB_BUILD_SHARED_LIBS)
+    install_local_dependency_libs(ZLIB ZLIB)
+endif()
diff --git a/src/cmake/build_minizip-ng.cmake b/src/cmake/build_minizip-ng.cmake
index c09e375fb6..4de964fb4e 100644
--- a/src/cmake/build_minizip-ng.cmake
+++ b/src/cmake/build_minizip-ng.cmake
@@ -14,7 +14,7 @@ set (minizip-ng_GIT_TAG "${minizip-ng_BUILD_VERSION}")
 set_cache (minizip-ng_BUILD_SHARED_LIBS OFF
            DOC "Should a local minizip-ng build, if necessary, build shared libraries" ADVANCED)
 
-checked_find_package (ZLIB REQUIRED)
+find_package (ZLIB REQUIRED)
 
 
 build_dependency_with_cmake(minizip-ng
@@ -45,8 +45,6 @@ build_dependency_with_cmake(minizip-ng
         -D MZ_ICONV=OFF
         -D MZ_FETCH_LIBS=OFF
         -D MZ_FORCE_FETCH_LIBS=OFF
-        -D ZLIB_LIBRARY=${ZLIB_LIBRARIES}
-        -D ZLIB_INCLUDE_DIR=${ZLIB_INCLUDE_DIRS}
     )
 
 
diff --git a/src/cmake/externalpackages.cmake b/src/cmake/externalpackages.cmake
index 6cb6aaf507..bbbd986787 100644
--- a/src/cmake/externalpackages.cmake
+++ b/src/cmake/externalpackages.cmake
@@ -37,7 +37,28 @@ include (FindThreads)
 # Dependencies for required formats and features. These are so critical
 # that we will not complete the build if they are not found.
 
-checked_find_package (ZLIB REQUIRED)  # Needed by several packages
+# ZLIB
+# We prefer zlib-ng to regular zlib, but we can use either.
+
+check_is_enabled(ZLIBNG ENABLE_ZLIBNG)
+check_is_enabled(ZLIB ALLOW_ZLIB)
+
+if (ENABLE_ZLIBNG)
+    # For zlib <= 1.3.1, we can differentiate between whether
+    # find_package(ZLIB ...) finds zlib-ng or zlib with the CONFIG
+    # or PREFER_CONFIG options.
+    if (ALLOW_ZLIB)
+        # Prefer zlib-ng if it's available, but fail over to zlib if it isn't.
+        checked_find_package (ZLIB PREFER_CONFIG REQUIRED)
+    else ()
+        checked_find_package (ZLIB CONFIG REQUIRED)
+    endif ()
+else ()
+    # Starting v1.3.2, zlib will export CMake configs; so once zlib-1.3.2+
+    # starts shipping with distros, we will have to re-evaluate how (and if)
+    # we support "ignoring" compatibility-mode-zlib-ng in favor of system zlib.
+    checked_find_package (ZLIB REQUIRED)
+endif ()
 
 # Help set up this target for libtiff config file when using static libtiff
 if (NOT TARGET CMath::CMath)