diff --git a/Doc/library/sys.rst b/Doc/library/sys.rst
index 305881a2e591d3..45ab50c47d3bc6 100644
--- a/Doc/library/sys.rst
+++ b/Doc/library/sys.rst
@@ -199,6 +199,15 @@ always available. Unless explicitly noted otherwise, all variables are read-only
    .. versionadded:: 3.3
 
 
+.. data:: build_prefix
+
+   Set during Python startup, before ``site.py`` is run. If running Python from
+   source, the value will be set to the build path, otherwise it will be set to
+   :const:`None`.
+
+   .. versionadded:: 3.12
+
+
 .. data:: byteorder
 
    An indicator of the native byte order.  This will have the value ``'big'`` on
diff --git a/Include/cpython/initconfig.h b/Include/cpython/initconfig.h
index 846e05fb26a4d8..920ea3eb95da79 100644
--- a/Include/cpython/initconfig.h
+++ b/Include/cpython/initconfig.h
@@ -210,6 +210,7 @@ typedef struct PyConfig {
     wchar_t *base_prefix;
     wchar_t *exec_prefix;
     wchar_t *base_exec_prefix;
+    wchar_t *build_prefix;
 
     /* --- Parameter only used by Py_Main() ---------- */
     int skip_source_first_line;
diff --git a/Lib/sysconfig/__init__.py b/Lib/sysconfig/__init__.py
index 0657e458806e9b..20a55174afe05b 100644
--- a/Lib/sysconfig/__init__.py
+++ b/Lib/sysconfig/__init__.py
@@ -221,13 +221,14 @@ def _safe_realpath(path):
 if "_PYTHON_PROJECT_BASE" in os.environ:
     _PROJECT_BASE = _safe_realpath(os.environ["_PYTHON_PROJECT_BASE"])
 
-def is_python_build():
-    for fn in ("Setup", "Setup.local"):
-        if os.path.isfile(os.path.join(_PROJECT_BASE, "Modules", fn)):
-            return True
-    return False
-
-_PYTHON_BUILD = is_python_build()
+def is_python_build(check_home=None):
+    if check_home is not None:
+        import warnings
+        warnings.warn("check_home argument is deprecated and ignored.",
+                      DeprecationWarning, stacklevel=2)
+    return bool(sys.build_prefix)
+
+_PYTHON_BUILD = bool(sys.build_prefix)
 
 if _PYTHON_BUILD:
     for scheme in ('posix_prefix', 'posix_home'):
diff --git a/Lib/test/test_embed.py b/Lib/test/test_embed.py
index 8ef2bcc3249b8b..562ee69218c4b3 100644
--- a/Lib/test/test_embed.py
+++ b/Lib/test/test_embed.py
@@ -1099,6 +1099,9 @@ def check_all_configs(self, testname, expected_config=None,
         except json.JSONDecodeError:
             self.fail(f"fail to decode stdout: {out!r}")
 
+        # build_prefix depends on if Python was installed, ignore it here
+        configs['config'].pop('build_prefix', None)
+
         self.check_pre_config(configs, expected_preconfig)
         self.check_config(configs, expected_config)
         self.check_global_config(configs)
diff --git a/Lib/test/test_sys.py b/Lib/test/test_sys.py
index c6056154e2d037..f19147519c95fc 100644
--- a/Lib/test/test_sys.py
+++ b/Lib/test/test_sys.py
@@ -775,6 +775,7 @@ def test_attributes(self):
         self.assertIsInstance(sys.platform, str)
         self.assertIsInstance(sys.prefix, str)
         self.assertIsInstance(sys.base_prefix, str)
+        self.assertIsInstance(sys.build_prefix, (str, None))
         self.assertIsInstance(sys.platlibdir, str)
         self.assertIsInstance(sys.version, str)
         vi = sys.version_info
diff --git a/Misc/NEWS.d/next/Library/2022-11-09-03-07-26.gh-issue-98718.rY4eIr.rst b/Misc/NEWS.d/next/Library/2022-11-09-03-07-26.gh-issue-98718.rY4eIr.rst
new file mode 100644
index 00000000000000..bd7bd9636c0510
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2022-11-09-03-07-26.gh-issue-98718.rY4eIr.rst
@@ -0,0 +1,2 @@
+:mod:`sys` now exports :attr:`sys.build_prefix`, with the path of the Python
+build directory, if any.
diff --git a/Modules/getpath.py b/Modules/getpath.py
index f5f928f1795de5..d3cc7be3177b3b 100644
--- a/Modules/getpath.py
+++ b/Modules/getpath.py
@@ -544,6 +544,9 @@ def search_up(prefix, *landmarks, test=isfile):
         config['_is_python_build'] = 1
 
 
+config['build_prefix'] = build_prefix
+
+
 # ******************************************************************************
 # CALCULATE prefix AND exec_prefix
 # ******************************************************************************
diff --git a/Python/initconfig.c b/Python/initconfig.c
index 225ee0a3fe5ff2..ed357f8a654a4b 100644
--- a/Python/initconfig.c
+++ b/Python/initconfig.c
@@ -114,6 +114,7 @@ static const PyConfigSpec PYCONFIG_SPEC[] = {
     SPEC(base_exec_prefix, WSTR_OPT, PUBLIC, SYS_ATTR("base_exec_prefix")),
     SPEC(base_executable, WSTR_OPT, PUBLIC, SYS_ATTR("_base_executable")),
     SPEC(base_prefix, WSTR_OPT, PUBLIC, SYS_ATTR("base_prefix")),
+    SPEC(build_prefix, WSTR_OPT, PUBLIC, SYS_ATTR("build_prefix")),
     SPEC(bytes_warning, UINT, PUBLIC, SYS_FLAG(9)),
     SPEC(cpu_count, INT, PUBLIC, NO_SYS),
     SPEC(lazy_imports, INT, PUBLIC, NO_SYS),
@@ -1088,6 +1089,7 @@ PyConfig_Clear(PyConfig *config)
     CLEAR(config->base_prefix);
     CLEAR(config->exec_prefix);
     CLEAR(config->base_exec_prefix);
+    CLEAR(config->build_prefix);
     CLEAR(config->platlibdir);
     CLEAR(config->sys_path_0);
 
@@ -3965,6 +3967,7 @@ _Py_DumpPathConfig(PyThreadState *tstate)
     DUMP_SYS(_base_executable);
     DUMP_SYS(base_prefix);
     DUMP_SYS(base_exec_prefix);
+    DUMP_SYS(build_prefix);
     DUMP_SYS(platlibdir);
     DUMP_SYS(executable);
     DUMP_SYS(prefix);
diff --git a/Python/sysmodule.c b/Python/sysmodule.c
index ce75027f67e9f4..4dfaa031fa7d81 100644
--- a/Python/sysmodule.c
+++ b/Python/sysmodule.c
@@ -4202,6 +4202,7 @@ _PySys_UpdateConfig(PyThreadState *tstate)
     COPY_WSTR("exec_prefix", config->exec_prefix);
     COPY_WSTR("base_exec_prefix", config->base_exec_prefix);
     COPY_WSTR("platlibdir", config->platlibdir);
+    COPY_WSTR("build_prefix", config->build_prefix);
 
     if (config->pycache_prefix != NULL) {
         SET_SYS_FROM_WSTR("pycache_prefix", config->pycache_prefix);