diff --git a/test/1_stdlib/timeout.sh b/test/1_stdlib/timeout.sh
index 1d1bfe490666d..b0a8f5049bca1 100755
--- a/test/1_stdlib/timeout.sh
+++ b/test/1_stdlib/timeout.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 # timeout.sh <seconds> <command...>
 
diff --git a/utils/benchmark/build.sh b/utils/benchmark/build.sh
index e857ac22ebcbf..809c9b29c2a27 100755
--- a/utils/benchmark/build.sh
+++ b/utils/benchmark/build.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 if [[ -n "$LLVM_DIR" ]]; then
     BUILD_DIR="$LLVM_DIR/build"
diff --git a/utils/build-script b/utils/build-script
index d75e2ef04a2d4..44f2553b0fefb 100755
--- a/utils/build-script
+++ b/utils/build-script
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 #===--- build-script - The ultimate tool for building Swift ----------------===#
 #
 ## This source file is part of the Swift.org open source project
diff --git a/utils/build-script-impl b/utils/build-script-impl
index e7267835034fe..8887c0f31373d 100755
--- a/utils/build-script-impl
+++ b/utils/build-script-impl
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #===--- build-script-impl - Implementation details of build-script ---------===#
 #
 ## This source file is part of the Swift.org open source project
diff --git a/utils/darwin-installer-scripts/postinstall b/utils/darwin-installer-scripts/postinstall
index af8d2cc73b63e..273073c826dd9 100755
--- a/utils/darwin-installer-scripts/postinstall
+++ b/utils/darwin-installer-scripts/postinstall
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #===--- postinstall - Creates symlink after installing xctoolchain ----------===#
 #
 ## This source file is part of the Swift.org open source project
diff --git a/utils/omit-needless-words.py b/utils/omit-needless-words.py
index c6a38e7077942..4a6f0f13d6b5a 100755
--- a/utils/omit-needless-words.py
+++ b/utils/omit-needless-words.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 # This tool helps assess the impact of automatically applying
 # heuristics that omit 'needless' words from APIs imported from Clang
diff --git a/utils/pygments/swift.py b/utils/pygments/swift.py
index 93bf7aca33cf2..b626e53f22daa 100644
--- a/utils/pygments/swift.py
+++ b/utils/pygments/swift.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 import re
 
diff --git a/utils/recursive-lipo b/utils/recursive-lipo
index 7d1c84840e846..e2a4a3cac3a9d 100755
--- a/utils/recursive-lipo
+++ b/utils/recursive-lipo
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 import argparse
 import os.path
diff --git a/utils/resolve-crashes.py b/utils/resolve-crashes.py
index 34c33da3b2022..c6c7434659a52 100755
--- a/utils/resolve-crashes.py
+++ b/utils/resolve-crashes.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 
 # A small utility to take the output of a Swift validation test run
 # where some compiler crashers have been fixed, and move them into the
diff --git a/utils/sil-opt-verify-all-modules.py b/utils/sil-opt-verify-all-modules.py
index 6588f198e8b8f..0bc6f9fed7400 100755
--- a/utils/sil-opt-verify-all-modules.py
+++ b/utils/sil-opt-verify-all-modules.py
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 #===------------------------------------------------------------------------===#
 #
 # This source file is part of the Swift.org open source project
diff --git a/utils/swift-stdlib-tool-substitute b/utils/swift-stdlib-tool-substitute
index 7e6ed10acb582..bee61afc9b806 100755
--- a/utils/swift-stdlib-tool-substitute
+++ b/utils/swift-stdlib-tool-substitute
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 #===--- swift-stdlib-tool - stand-in for the real swift-stdlib-tool --------===#
 #
diff --git a/utils/toolchain-codesign b/utils/toolchain-codesign
index 81c7b364d2689..2d8ba94ee246a 100755
--- a/utils/toolchain-codesign
+++ b/utils/toolchain-codesign
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #===--- toolchain-codesign - Creates code signed xctoolchain ---------------===#
 #
 ## This source file is part of the Swift.org open source project
diff --git a/utils/toolchain-installer b/utils/toolchain-installer
index 61f7a4fe294c5..f3e3902383df0 100755
--- a/utils/toolchain-installer
+++ b/utils/toolchain-installer
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 #===--- toolchain-installer - Creates installer pkg for OS X ---------------===#
 #
 ## This source file is part of the Swift.org open source project
diff --git a/utils/update-checkout b/utils/update-checkout
index 3dd11af9a027e..94d952340607a 100755
--- a/utils/update-checkout
+++ b/utils/update-checkout
@@ -1,4 +1,4 @@
-#!/usr/bin/python
+#!/usr/bin/env python
 #===--- update-checkout - Utility to update your local checkouts -----------===#
 #
 # This source file is part of the Swift.org open source project
diff --git a/validation-test/SIL/Inputs/gen_parse_stdlib_tests.sh b/validation-test/SIL/Inputs/gen_parse_stdlib_tests.sh
index 873abafe8f4d7..82665057976ec 100755
--- a/validation-test/SIL/Inputs/gen_parse_stdlib_tests.sh
+++ b/validation-test/SIL/Inputs/gen_parse_stdlib_tests.sh
@@ -1,4 +1,4 @@
-#!/bin/bash
+#!/usr/bin/env bash
 
 process_count=17
 process_id_max=$(($process_count - 1))