diff --git a/cmake/FindO2.cmake b/cmake/FindO2.cmake
index 421d52af182..800348cec9b 100644
--- a/cmake/FindO2.cmake
+++ b/cmake/FindO2.cmake
@@ -1,59 +1,30 @@
-# Find O2
-# ~~~~~~~~~
-# Copyright (c) 2016, Monsanto Company, USA
-# Author: Larry Shaffer, <lshaffer (at) boundlessgeo (dot) com>
+# FindO2.cmake - Find the O2 library using pkg-config
 #
-# Redistribution and use is allowed according to the terms of the BSD license.
-# For details see the accompanying COPYING-CMAKE-SCRIPTS file.
-#
-# CMake module to search for O2 OAuth 1/2 library from:
-#    https://github.com/pipacs/o2
-#
-# If it's found it sets O2_FOUND to TRUE
-# and following variables are set:
-#    O2_INCLUDE_DIR
-#    O2_LIBRARY
-#    O2_LIBRARY_STATIC
+# This module defines:
+# - `O2_FOUND` - Set to TRUE if the library is found.
+# - `O2_INCLUDE_DIRS` - Include directories for the library.
+# - `O2_LIBRARIES` - Libraries to link against.
+# - The alias target `o2::o2` if the library is found.
 
-IF (O2_INCLUDE_DIR AND (O2_LIBRARY OR O2_LIBRARY_STATIC))
-   SET(O2_FOUND TRUE)
+find_package(PkgConfig REQUIRED)
 
-ELSE (O2_INCLUDE_DIR AND (O2_LIBRARY OR O2_LIBRARY_STATIC))
+pkg_search_module(PC_O2 IMPORTED_TARGET o2)
 
-  FIND_PATH(O2_INCLUDE_DIR o2.h
-    PATHS
-    /usr/include
-    /usr/local/include
-    "$ENV{LIB_DIR}/include"
-    $ENV{INCLUDE}
-    PATH_SUFFIXES o2
-    )
-  FIND_LIBRARY(O2_LIBRARY NAMES o2
-    PATHS
-    /usr/local/lib
-    /usr/lib
-    "$ENV{LIB_DIR}/lib"
-    "$ENV{LIB}"
-    )
-  FIND_LIBRARY(O2_LIBRARY_STATIC NAMES libo2.a libo2_static.a o2_static
-    PATHS
-    /usr/local/lib
-    /usr/lib
-    "$ENV{LIB_DIR}/lib"
-    "$ENV{LIB}"
-    )
+if (PC_O2_FOUND)
+    set(O2_FOUND TRUE)
+    set(O2_INCLUDE_DIRS ${PC_O2_INCLUDE_DIRS})
+    set(O2_LIBRARIES ${PC_O2_LIBRARIES})
 
-  include(FindPackageHandleStandardArgs)
-  find_package_handle_standard_args(O2 DEFAULT_MSG O2_LIBRARY O2_INCLUDE_DIR)
+    add_library(o2::o2 ALIAS PkgConfig::PC_O2)
+else()
+    set(O2_FOUND FALSE)
+    if (NOT O2_FIND_QUIETLY)
+        message(WARNING "O2 library not found via pkg-config.")
+    endif()
+    if (O2_FIND_REQUIRED)
+        message(FATAL_ERROR "O2 library is required but was not found.")
+    endif()
+endif()
 
-ENDIF (O2_INCLUDE_DIR AND (O2_LIBRARY OR O2_LIBRARY_STATIC))
-
-IF (O2_FOUND)
-   IF (NOT O2_FIND_QUIETLY)
-      MESSAGE(STATUS "Found O2: ${O2_LIBRARY} ${O2_LIBRARY_STATIC}")
-   ENDIF (NOT O2_FIND_QUIETLY)
-ELSE (O2_FOUND)
-   IF (O2_FIND_REQUIRED)
-      MESSAGE(FATAL_ERROR "Could not find O2")
-   ENDIF (O2_FIND_REQUIRED)
-ENDIF (O2_FOUND)
+# Mark results for cache
+mark_as_advanced(O2_INCLUDE_DIRS O2_LIBRARIES)
diff --git a/src/auth/oauth2/CMakeLists.txt b/src/auth/oauth2/CMakeLists.txt
index 5f993144637..a4348cf48f5 100644
--- a/src/auth/oauth2/CMakeLists.txt
+++ b/src/auth/oauth2/CMakeLists.txt
@@ -3,7 +3,12 @@
 ########################################################
 # Packages
 
-option(WITH_INTERNAL_O2 "Download and locally include source of o2 library" ON)
+if(WITH_VGPKG)
+  set(WITH_INTERNAL_O2_DEFAULT OFF)
+else()
+  set(WITH_INTERNAL_O2_DEFAULT ON)
+endif()
+option(WITH_INTERNAL_O2 "Download and locally include source of o2 library" ${WITH_INTERNAL_O2_DEFAULT})
 
 if(WITH_INTERNAL_O2)
   set(O2_SOURCE_DIR ${CMAKE_SOURCE_DIR}/external/o2/src)
@@ -113,12 +118,7 @@ target_link_libraries(authmethod_oauth2_a qgis_core)
 if(WITH_INTERNAL_O2)
   target_include_directories(authmethod_oauth2_a SYSTEM PUBLIC ${O2_INCLUDE_DIR})
 else()
-  if(NOT "${O2_LIBRARY}" STREQUAL "")
-    # prefer dynamic linking
-    target_link_libraries(authmethod_oauth2_a ${O2_LIBRARY})
-  else()
-    target_link_libraries(authmethod_oauth2_a ${O2_LIBRARY_STATIC})
-  endif()
+  target_link_libraries(authmethod_oauth2_a o2::o2)
 endif()
 
 target_include_directories(authmethod_oauth2_a PRIVATE
@@ -154,12 +154,7 @@ else()
   if(WITH_INTERNAL_O2)
     target_include_directories(authmethod_oauth2 SYSTEM PUBLIC ${O2_INCLUDE_DIR})
   else()
-    if(NOT "${O2_LIBRARY}" STREQUAL "")
-      # prefer dynamic linking
-      target_link_libraries(authmethod_oauth2 ${O2_LIBRARY})
-    else()
-      target_link_libraries(authmethod_oauth2 ${O2_LIBRARY_STATIC})
-    endif()
+    target_link_libraries(authmethod_oauth2 o2::o2)
   endif()
 
   if(WIN32)
diff --git a/vcpkg/ports/o2/portfile.cmake b/vcpkg/ports/o2/portfile.cmake
new file mode 100644
index 00000000000..dc4edf73e94
--- /dev/null
+++ b/vcpkg/ports/o2/portfile.cmake
@@ -0,0 +1,22 @@
+vcpkg_from_github(
+    OUT_SOURCE_PATH SOURCE_PATH
+    REPO qgis/o2
+    REF "v${VERSION}"
+    SHA512 e0116a8f72e8c98ef4237e36598a8f246319a30bb5bfab629e3220e7b819b1e9028c2e6caa4c92f17c4b0548c94c242120c5b4750abce2441a2db5d88b2e22f5
+    HEAD_REF master
+)
+
+vcpkg_cmake_configure(
+    DISABLE_PARALLEL_CONFIGURE
+    SOURCE_PATH ${SOURCE_PATH}
+    OPTIONS
+        -Do2_WITH_QT6=ON
+        -Do2_WITH_KEYCHAIN=ON
+)
+vcpkg_cmake_install()
+vcpkg_fixup_pkgconfig()
+
+vcpkg_copy_pdbs()
+
+# Handle copyright
+file(INSTALL "${SOURCE_PATH}/LICENSE" DESTINATION "${CURRENT_PACKAGES_DIR}/share/${PORT}" RENAME copyright)
diff --git a/vcpkg/ports/o2/vcpkg.json b/vcpkg/ports/o2/vcpkg.json
new file mode 100644
index 00000000000..2f9f5e30a38
--- /dev/null
+++ b/vcpkg/ports/o2/vcpkg.json
@@ -0,0 +1,18 @@
+{
+  "name": "o2",
+  "version": "1",
+  "description": "OAuth 2.0 for Qt",
+  "homepage": "https://github.com/qgis/o2",
+  "license": "BSD-2-Clause",
+  "dependencies": [
+    "qtkeychain-qt6",
+    {
+      "name": "vcpkg-cmake",
+      "host": true
+    },
+    {
+      "name": "vcpkg-cmake-config",
+      "host": true
+    }
+  ]
+}
diff --git a/vcpkg/vcpkg.json b/vcpkg/vcpkg.json
index c84511c7018..0aaff002402 100644
--- a/vcpkg/vcpkg.json
+++ b/vcpkg/vcpkg.json
@@ -61,6 +61,7 @@
     "libzip",
     "meshoptimizer",
     "nlohmann-json",
+    "o2",
     "pdal",
     "proj",
     "protobuf",