diff --git a/source/Calamari.Common/Features/Scripting/Bash/BashScriptBootstrapper.cs b/source/Calamari.Common/Features/Scripting/Bash/BashScriptBootstrapper.cs
index 5822ec1792..f97b2dd043 100644
--- a/source/Calamari.Common/Features/Scripting/Bash/BashScriptBootstrapper.cs
+++ b/source/Calamari.Common/Features/Scripting/Bash/BashScriptBootstrapper.cs
@@ -148,7 +148,12 @@ public static (string bootstrapFile, string[] temporaryFiles) PrepareBootstrapFi
                 writer.NewLine = LinuxNewLine;
                 writer.WriteLine("#!/bin/bash");
                 writer.WriteLine("source \"$(pwd)/" + Path.GetFileName(configurationFile) + "\"");
-                writer.WriteLine("shift"); // Shift the variable decryption key out of scope of the user script (see: https://github.com/OctopusDeploy/Calamari/pull/773)
+                writer.WriteLine("shift"); // Shift the variable decryption key out of scope of the user script and script modules (see: https://github.com/OctopusDeploy/Calamari/pull/773)
+                
+                var preloadModules = variables.Get(BashScriptVariables.PreloadScriptModules);
+                if (!string.IsNullOrWhiteSpace(preloadModules))
+                    PreloadScriptModules(writer, preloadModules, scriptModulePaths);
+                    
                 writer.WriteLine("source \"$(pwd)/" + Path.GetFileName(script.File) + "\" " + script.Parameters);
                 writer.Flush();
             }
@@ -158,6 +163,23 @@ public static (string bootstrapFile, string[] temporaryFiles) PrepareBootstrapFi
             return (bootstrapFile, scriptModulePaths);
         }
 
+
+        static void PreloadScriptModules(StreamWriter writer, string preloadModules, string[] scriptModulePaths)
+        {
+            var modules = preloadModules.Split(new[] { ',', ';' }, StringSplitOptions.RemoveEmptyEntries);
+            foreach (var module in modules)
+            {
+                var sanitizedName = ScriptVariables.FormatScriptName(module.Trim());
+                var fileName = $"{sanitizedName}.sh";
+                var scriptModule = scriptModulePaths.FirstOrDefault(p => string.Equals(Path.GetFileName(p), fileName, StringComparison.OrdinalIgnoreCase));
+                if (scriptModule != null)
+                {
+                    Log.VerboseFormat("Preloading script module '{0}'.", module.Trim());
+                    writer.WriteLine("source \"$(pwd)/" + fileName + "\"");
+                }
+            }
+        }
+
         static IEnumerable<string> PrepareScriptModules(IVariables variables, string workingDirectory)
         {
             foreach (var variableName in variables.GetNames().Where(ScriptVariables.IsLibraryScriptModule))
diff --git a/source/Calamari.Common/Features/Scripting/Bash/BashScriptVariables.cs b/source/Calamari.Common/Features/Scripting/Bash/BashScriptVariables.cs
new file mode 100644
index 0000000000..fead467ec7
--- /dev/null
+++ b/source/Calamari.Common/Features/Scripting/Bash/BashScriptVariables.cs
@@ -0,0 +1,7 @@
+namespace Calamari.Common.Features.Scripting.Bash
+{
+    public static class BashScriptVariables
+    {
+        public static readonly string PreloadScriptModules = "Octopus.Action.Script.PreloadScriptModules";
+    }
+}
diff --git a/source/Calamari.Tests/Fixtures/Bash/BashFixture.cs b/source/Calamari.Tests/Fixtures/Bash/BashFixture.cs
index 52bbb0a127..070828a62c 100644
--- a/source/Calamari.Tests/Fixtures/Bash/BashFixture.cs
+++ b/source/Calamari.Tests/Fixtures/Bash/BashFixture.cs
@@ -352,6 +352,126 @@ public void ShouldBeAbleToEnumerateVariableValues(FeatureToggle? featureToggle)
             output.AssertOutput("Key: VariableName`prop`anotherprop` 13, Value: Value`prop`13");
             output.AssertOutput($"Key: {specialCharacters}, Value: {specialCharacters}");
         }
+
+        [Test]
+        [RequiresBashDotExeIfOnWindows]
+        public void ShouldPreloadScriptModules()
+        {
+            var (output, _) = RunScript("preload-modules.sh",
+                                        new Dictionary<string, string>()
+                                        {
+                                            ["Octopus.Script.Module[test_module]"] = @"function test_function {
+  echo ""Function from preloaded module""
+}
+
+export PRELOADED_VAR=""module_value""",
+                                            ["Octopus.Script.Module.Language[test_module]"] = "Bash",
+                                            ["Octopus.Action.Script.PreloadScriptModules"] = "test_module"
+                                        });
+
+            Assert.Multiple(() =>
+            {
+                output.AssertSuccess();
+                output.AssertOutput("Calling test_function from preloaded module...");
+                output.AssertOutput("Function from preloaded module");
+                output.AssertOutput("Checking preloaded variable...");
+                output.AssertOutput("PRELOADED_VAR=module_value");
+            });
+        }
+
+        [Test]
+        [RequiresBashDotExeIfOnWindows]
+        public void ShouldPreloadMultipleScriptModulesInOrder()
+        {
+            var (output, _) = RunScript("preload-modules.sh",
+                                        new Dictionary<string, string>()
+                                        {
+                                            ["Octopus.Script.Module[module1]"] = @"function test_function {
+  echo ""Module 1""
+}
+
+export PRELOADED_VAR=""value1""",
+                                            ["Octopus.Script.Module.Language[module1]"] = "Bash",
+                                            ["Octopus.Script.Module[module2]"] = @"function test_function {
+  echo ""Module 2""
+}
+
+export PRELOADED_VAR=""value2""",
+                                            ["Octopus.Script.Module.Language[module2]"] = "Bash",
+                                            // module2 sourced last, so it wins
+                                            ["Octopus.Action.Script.PreloadScriptModules"] = "module1,module2"
+                                        });
+
+            Assert.Multiple(() =>
+            {
+                output.AssertSuccess();
+                // Should use module2's function (last wins)
+                output.AssertOutput("Module 2");
+                // Should use module2's variable (last wins)
+                output.AssertOutput("PRELOADED_VAR=value2");
+            });
+        }
+
+        [Test]
+        [RequiresBashDotExeIfOnWindows]
+        [TestCase("module1,module2", "module1,module2")]
+        [TestCase("module1, module2", "module1,module2")]
+        [TestCase("module1 , module2", "module1,module2")]
+        [TestCase("module1;module2", "module1,module2")]
+        [TestCase("module1; module2", "module1,module2")]
+        [TestCase("module1 ; module2", "module1,module2")]
+        [TestCase("module1,module2;module3", "module1,module2,module3")]
+        [TestCase("module1, module2; module3", "module1,module2,module3")]
+        [TestCase("module1,,module2", "module1,module2")]
+        [TestCase(" module1 , module2 ", "module1,module2")]
+        [TestCase("module1,  ,module2", "module1,module2")]
+        [TestCase("module1,missing_module", "module1")]
+        public void PreloadModulesShouldHandleVariousDelimiterCombinations(string moduleList, string expectedModules)
+        {
+            var (output, _) = RunScript("preload-modules.sh",
+                                        new Dictionary<string, string>()
+                                        {
+                                            ["Octopus.Script.Module[module1]"] = @"function test_function {
+  echo ""Module 1""
+}
+
+if [ -z ""$PRELOADED_VAR"" ]; then
+  export PRELOADED_VAR=""module1""
+else
+  export PRELOADED_VAR=""$PRELOADED_VAR,module1""
+fi",
+                                            ["Octopus.Script.Module.Language[module1]"] = "Bash",
+                                            ["Octopus.Script.Module[module2]"] = @"function test_function {
+  echo ""Module 2""
+}
+
+if [ -z ""$PRELOADED_VAR"" ]; then
+  export PRELOADED_VAR=""module2""
+else
+  export PRELOADED_VAR=""$PRELOADED_VAR,module2""
+fi",
+                                            ["Octopus.Script.Module.Language[module2]"] = "Bash",
+                                            ["Octopus.Script.Module[module3]"] = @"function test_function {
+  echo ""Module 3""
+}
+
+if [ -z ""$PRELOADED_VAR"" ]; then
+  export PRELOADED_VAR=""module3""
+else
+  export PRELOADED_VAR=""$PRELOADED_VAR,module3""
+fi",
+                                            ["Octopus.Script.Module.Language[module3]"] = "Bash",
+                                            ["Octopus.Action.Script.PreloadScriptModules"] = moduleList
+                                        });
+
+            Assert.Multiple(() =>
+            {
+                output.AssertSuccess();
+
+                // Verify expected modules were loaded in the correct order
+                output.AssertOutput($"PRELOADED_VAR={expectedModules}");
+            });
+        }
     }
 
     public static class AdditionalVariablesExtensions
diff --git a/source/Calamari.Tests/Fixtures/Bash/Scripts/preload-modules.sh b/source/Calamari.Tests/Fixtures/Bash/Scripts/preload-modules.sh
new file mode 100644
index 0000000000..bfe95cae1b
--- /dev/null
+++ b/source/Calamari.Tests/Fixtures/Bash/Scripts/preload-modules.sh
@@ -0,0 +1,8 @@
+#!/bin/bash
+
+# Test that preloaded modules are available
+echo "Calling test_function from preloaded module..."
+test_function
+
+echo "Checking preloaded variable..."
+echo "PRELOADED_VAR=$PRELOADED_VAR"