diff --git a/icu4c/as_is/bomlist.py b/icu4c/as_is/bomlist.py
index b606dc86c5e..ae28c25627d 100755
--- a/icu4c/as_is/bomlist.py
+++ b/icu4c/as_is/bomlist.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python -B
 
 # Copyright (C) 2016 and later: Unicode, Inc. and others.
 # License & terms of use: http://www.unicode.org/copyright.html
diff --git a/icu4c/source/test/depstest/dependencies.py b/icu4c/source/test/depstest/dependencies.py
index 87bbc8cdfb4..f4e7a7d4751 100755
--- a/icu4c/source/test/depstest/dependencies.py
+++ b/icu4c/source/test/depstest/dependencies.py
@@ -1,4 +1,4 @@
-#! /usr/bin/python
+#! /usr/bin/python -B
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) 2016 and later: Unicode, Inc. and others.
diff --git a/icu4c/source/test/depstest/depstest.py b/icu4c/source/test/depstest/depstest.py
index 2a542e78707..231c6819c6e 100755
--- a/icu4c/source/test/depstest/depstest.py
+++ b/icu4c/source/test/depstest/depstest.py
@@ -1,4 +1,4 @@
-#! /usr/bin/python
+#! /usr/bin/python -B
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) 2016 and later: Unicode, Inc. and others.
diff --git a/icu4c/source/tools/icu-svnprops-check.py b/icu4c/source/tools/icu-svnprops-check.py
index b0e86b3e88c..313da136884 100755
--- a/icu4c/source/tools/icu-svnprops-check.py
+++ b/icu4c/source/tools/icu-svnprops-check.py
@@ -1,4 +1,4 @@
-#! /usr/bin/python
+#! /usr/bin/python -B
 
 # Copyright (C) 2016 and later: Unicode, Inc. and others.
 # License & terms of use: http://www.unicode.org/copyright.html
diff --git a/tools/release/c/bomfix.py b/tools/release/c/bomfix.py
index 99c393bdb8f..300fc629e5f 100644
--- a/tools/release/c/bomfix.py
+++ b/tools/release/c/bomfix.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python -B
 # -*- coding: utf-8 -*-
 
 #
diff --git a/tools/scripts/bldicures.py b/tools/scripts/bldicures.py
index b7673ef7929..920c977fc57 100755
--- a/tools/scripts/bldicures.py
+++ b/tools/scripts/bldicures.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python -B
 #
 # Copyright (C) 2017 and later: Unicode, Inc. and others.
 # License & terms of use: http://www.unicode.org/copyright.html
diff --git a/tools/unicode/c/genprops/misc/ucdcopy.py b/tools/unicode/c/genprops/misc/ucdcopy.py
index 0bae46ba099..9c196352caa 100755
--- a/tools/unicode/c/genprops/misc/ucdcopy.py
+++ b/tools/unicode/c/genprops/misc/ucdcopy.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python2.4
+#!/usr/bin/python2.4 -B
 #
 # Copyright (C) 2017 and later: Unicode, Inc. and others.
 # License & terms of use: http://www.unicode.org/copyright.html
diff --git a/tools/unicode/c/genuca/genteststub.py b/tools/unicode/c/genuca/genteststub.py
index c394cea677e..3708f76d1b5 100755
--- a/tools/unicode/c/genuca/genteststub.py
+++ b/tools/unicode/c/genuca/genteststub.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python -B
 #
 # Copyright (C) 2017 and later: Unicode, Inc. and others.
 # License & terms of use: http://www.unicode.org/copyright.html
diff --git a/tools/unicode/py/parsescriptmetadata.py b/tools/unicode/py/parsescriptmetadata.py
index 80b4ac42da7..626dac3dd63 100755
--- a/tools/unicode/py/parsescriptmetadata.py
+++ b/tools/unicode/py/parsescriptmetadata.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python -B
 # -*- coding: utf-8 -*-
 #
 # Copyright (C) 2017 and later: Unicode, Inc. and others.
diff --git a/tools/unicode/py/preparseucd.py b/tools/unicode/py/preparseucd.py
index d79ae451ac5..7850ef00670 100755
--- a/tools/unicode/py/preparseucd.py
+++ b/tools/unicode/py/preparseucd.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/python -B
 # -*- coding: utf-8 -*-
 # © 2016 and later: Unicode, Inc. and others.
 # License & terms of use: http://www.unicode.org/copyright.html