diff --git a/application.go b/application.go
index 0d07738..43242aa 100644
--- a/application.go
+++ b/application.go
@@ -23,6 +23,7 @@ import (
 	"fmt"
 	"io"
 	"sort"
+	"strings"
 	"sync"
 	"time"
 
@@ -168,6 +169,7 @@ func (a *Application) Command(name string) *Command {
 // there is only one. Returns nil if the command does not exist of if the fuzzy
 // matching find more than one.
 func (a *Application) BestCommand(name string) *Command {
+	name = strings.ToLower(name)
 	if c := a.Command(name); c != nil {
 		return c
 	}
@@ -188,6 +190,7 @@ func (a *Application) BestCommand(name string) *Command {
 
 // Category returns the named CommandCategory on App. Returns nil if the category does not exist
 func (a *Application) Category(name string) *CommandCategory {
+	name = strings.ToLower(name)
 	if a.Categories == nil {
 		return nil
 	}
@@ -315,6 +318,7 @@ func (a *Application) setup() {
 	registerAutocompleteCommands(a)
 
 	for _, c := range a.Commands {
+		c.normalizeCommandNames()
 		if c.HelpName == "" {
 			c.HelpName = fmt.Sprintf("%s %s", a.HelpName, c.FullName())
 		}
diff --git a/command.go b/command.go
index deb04f3..aba96d7 100644
--- a/command.go
+++ b/command.go
@@ -76,6 +76,15 @@ func Hide() bool {
 	return true
 }
 
+func (c *Command) normalizeCommandNames() {
+	c.Category = strings.ToLower(c.Category)
+	c.Name = strings.ToLower(c.Name)
+	c.HelpName = strings.ToLower(c.HelpName)
+	for _, alias := range c.Aliases {
+		alias.Name = strings.ToLower(alias.Name)
+	}
+}
+
 // FullName returns the full name of the command.
 // For subcommands this ensures that parent commands are part of the command path
 func (c *Command) FullName() string {
diff --git a/command_test.go b/command_test.go
index 03e863b..2aeb7a4 100644
--- a/command_test.go
+++ b/command_test.go
@@ -112,6 +112,38 @@ func TestCommand_Run_DoesNotOverwriteErrorFromBefore(t *testing.T) {
 	}
 }
 
+func TestCaseInsensitiveCommandNames(t *testing.T) {
+	app := Application{}
+	app.ErrWriter = io.Discard
+	projectList := &Command{Name: "project:LIST", Aliases: []*Alias{{Name: "FOO"}}}
+	projectLink := &Command{Name: "PROJECT:link"}
+	app.Commands = []*Command{
+		projectList,
+		projectLink,
+	}
+
+	app.setup()
+
+	if c := app.BestCommand("project:list"); c != projectList {
+		t.Fatalf("expected project:list, got %v", c)
+	}
+	if c := app.BestCommand("Project:lISt"); c != projectList {
+		t.Fatalf("expected project:list, got %v", c)
+	}
+	if c := app.BestCommand("project:link"); c != projectLink {
+		t.Fatalf("expected project:link, got %v", c)
+	}
+	if c := app.BestCommand("project:Link"); c != projectLink {
+		t.Fatalf("expected project:link, got %v", c)
+	}
+	if c := app.BestCommand("foo"); c != projectList {
+		t.Fatalf("expected project:link, got %v", c)
+	}
+	if c := app.BestCommand("FoO"); c != projectList {
+		t.Fatalf("expected project:link, got %v", c)
+	}
+}
+
 func TestFuzzyCommandNames(t *testing.T) {
 	app := Application{}
 	app.ErrWriter = io.Discard