diff --git a/builder/build.go b/builder/build.go
index 19145f55..d5d7a242 100644
--- a/builder/build.go
+++ b/builder/build.go
@@ -14,7 +14,6 @@ import (
 	"fmt"
 	"go/types"
 	"hash/crc32"
-	"io/ioutil"
 	"math/bits"
 	"os"
 	"os/exec"
@@ -103,7 +102,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 	}
 
 	// Create a temporary directory for intermediary files.
-	dir, err := ioutil.TempDir("", "tinygo")
+	dir, err := os.MkdirTemp("", "tinygo")
 	if err != nil {
 		return err
 	}
@@ -370,7 +369,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 				// Packages are compiled independently anyway.
 				for _, cgoHeader := range pkg.CGoHeaders {
 					// Store the header text in a temporary file.
-					f, err := ioutil.TempFile(dir, "cgosnippet-*.c")
+					f, err := os.CreateTemp(dir, "cgosnippet-*.c")
 					if err != nil {
 						return err
 					}
@@ -445,7 +444,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 				// Write to a temporary path that is renamed to the destination
 				// file to avoid race conditions with other TinyGo invocatiosn
 				// that might also be compiling this package at the same time.
-				f, err := ioutil.TempFile(filepath.Dir(job.result), filepath.Base(job.result))
+				f, err := os.CreateTemp(filepath.Dir(job.result), filepath.Base(job.result))
 				if err != nil {
 					return err
 				}
@@ -589,7 +588,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 				return err
 			}
 			defer llvmBuf.Dispose()
-			return ioutil.WriteFile(outpath, llvmBuf.Bytes(), 0666)
+			return os.WriteFile(outpath, llvmBuf.Bytes(), 0666)
 		case ".bc":
 			var buf llvm.MemoryBuffer
 			if config.UseThinLTO() {
@@ -598,10 +597,10 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 				buf = llvm.WriteBitcodeToMemoryBuffer(mod)
 			}
 			defer buf.Dispose()
-			return ioutil.WriteFile(outpath, buf.Bytes(), 0666)
+			return os.WriteFile(outpath, buf.Bytes(), 0666)
 		case ".ll":
 			data := []byte(mod.String())
-			return ioutil.WriteFile(outpath, data, 0666)
+			return os.WriteFile(outpath, data, 0666)
 		default:
 			panic("unreachable")
 		}
@@ -629,7 +628,7 @@ func Build(pkgName, outpath string, config *compileopts.Config, action func(Buil
 				}
 			}
 			defer llvmBuf.Dispose()
-			return ioutil.WriteFile(objfile, llvmBuf.Bytes(), 0666)
+			return os.WriteFile(objfile, llvmBuf.Bytes(), 0666)
 		},
 	}
 
diff --git a/builder/cc.go b/builder/cc.go
index 03c8c615..7d7c10ad 100644
--- a/builder/cc.go
+++ b/builder/cc.go
@@ -10,7 +10,6 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"sort"
@@ -93,7 +92,7 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, thinlto bool,
 	// Load dependencies file, if possible.
 	depfileName := "dep-" + depfileNameHash + ".json"
 	depfileCachePath := filepath.Join(goenv.Get("GOCACHE"), depfileName)
-	depfileBuf, err := ioutil.ReadFile(depfileCachePath)
+	depfileBuf, err := os.ReadFile(depfileCachePath)
 	var dependencies []string // sorted list of dependency paths
 	if err == nil {
 		// There is a dependency file, that's great!
@@ -117,12 +116,12 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, thinlto bool,
 		return "", err
 	}
 
-	objTmpFile, err := ioutil.TempFile(goenv.Get("GOCACHE"), "tmp-*"+ext)
+	objTmpFile, err := os.CreateTemp(goenv.Get("GOCACHE"), "tmp-*"+ext)
 	if err != nil {
 		return "", err
 	}
 	objTmpFile.Close()
-	depTmpFile, err := ioutil.TempFile(tmpdir, "dep-*.d")
+	depTmpFile, err := os.CreateTemp(tmpdir, "dep-*.d")
 	if err != nil {
 		return "", err
 	}
@@ -166,7 +165,7 @@ func compileAndCacheCFile(abspath, tmpdir string, cflags []string, thinlto bool,
 	sort.Strings(dependencySlice)
 
 	// Write dependencies file.
-	f, err := ioutil.TempFile(filepath.Dir(depfileCachePath), depfileName)
+	f, err := os.CreateTemp(filepath.Dir(depfileCachePath), depfileName)
 	if err != nil {
 		return "", err
 	}
@@ -267,7 +266,7 @@ func hashFile(path string) (string, error) {
 // allowed on Windows, but of course can be used on POSIX like systems. Still,
 // it's the most sane of any of the formats so readDepFile will use that format.
 func readDepFile(filename string) ([]string, error) {
-	buf, err := ioutil.ReadFile(filename)
+	buf, err := os.ReadFile(filename)
 	if err != nil {
 		return nil, err
 	}
diff --git a/builder/esp.go b/builder/esp.go
index bd348b54..e349c964 100644
--- a/builder/esp.go
+++ b/builder/esp.go
@@ -13,7 +13,7 @@ import (
 	"debug/elf"
 	"encoding/binary"
 	"fmt"
-	"io/ioutil"
+	"os"
 	"sort"
 	"strings"
 )
@@ -189,5 +189,5 @@ func makeESPFirmareImage(infile, outfile, format string) error {
 	}
 
 	// Write the image to the output file.
-	return ioutil.WriteFile(outfile, outf.Bytes(), 0666)
+	return os.WriteFile(outfile, outf.Bytes(), 0666)
 }
diff --git a/builder/library.go b/builder/library.go
index 1a2ed61c..d514568a 100644
--- a/builder/library.go
+++ b/builder/library.go
@@ -1,7 +1,6 @@
 package builder
 
 import (
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"runtime"
@@ -94,7 +93,7 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 	target := config.Triple()
 	if l.makeHeaders != nil {
 		if _, err = os.Stat(headerPath); err != nil {
-			temporaryHeaderPath, err := ioutil.TempDir(outdir, "include.tmp*")
+			temporaryHeaderPath, err := os.MkdirTemp(outdir, "include.tmp*")
 			if err != nil {
 				return nil, nil, err
 			}
@@ -189,7 +188,7 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 			defer once.Do(unlock)
 
 			// Create an archive of all object files.
-			f, err := ioutil.TempFile(outdir, "libc.a.tmp*")
+			f, err := os.CreateTemp(outdir, "libc.a.tmp*")
 			if err != nil {
 				return err
 			}
@@ -250,7 +249,7 @@ func (l *Library) load(config *compileopts.Config, tmpdir string) (job *compileJ
 			run: func(*compileJob) error {
 				var compileArgs []string
 				compileArgs = append(compileArgs, args...)
-				tmpfile, err := ioutil.TempFile(outdir, "crt1.o.tmp*")
+				tmpfile, err := os.CreateTemp(outdir, "crt1.o.tmp*")
 				if err != nil {
 					return err
 				}
diff --git a/builder/musl.go b/builder/musl.go
index 5dae0428..8a3716f0 100644
--- a/builder/musl.go
+++ b/builder/musl.go
@@ -3,7 +3,6 @@ package builder
 import (
 	"bytes"
 	"fmt"
-	"io/ioutil"
 	"os"
 	"path/filepath"
 	"regexp"
@@ -35,7 +34,7 @@ var Musl = Library{
 			filepath.Join(muslDir, "include", "alltypes.h.in"),
 		}
 		for _, infile := range infiles {
-			data, err := ioutil.ReadFile(infile)
+			data, err := os.ReadFile(infile)
 			if err != nil {
 				return err
 			}
@@ -63,7 +62,7 @@ var Musl = Library{
 		if err != nil {
 			return err
 		}
-		data, err := ioutil.ReadFile(filepath.Join(muslDir, "arch", arch, "bits", "syscall.h.in"))
+		data, err := os.ReadFile(filepath.Join(muslDir, "arch", arch, "bits", "syscall.h.in"))
 		if err != nil {
 			return err
 		}
diff --git a/builder/nrfutil.go b/builder/nrfutil.go
index 55aef45e..73b04925 100644
--- a/builder/nrfutil.go
+++ b/builder/nrfutil.go
@@ -2,7 +2,7 @@ package builder
 
 import (
 	"fmt"
-	"io/ioutil"
+	"io"
 	"os/exec"
 
 	"github.com/tinygo-org/tinygo/compileopts"
@@ -18,7 +18,7 @@ func makeDFUFirmwareImage(options *compileopts.Options, infile, outfile string)
 	}
 
 	cmd := exec.Command(cmdLine[0], cmdLine[1:]...)
-	cmd.Stdout = ioutil.Discard
+	cmd.Stdout = io.Discard
 	err := cmd.Run()
 	if err != nil {
 		return fmt.Errorf("could not run nrfutil pkg generate: %w", err)
diff --git a/builder/objcopy.go b/builder/objcopy.go
index 991bceba..cf10547b 100644
--- a/builder/objcopy.go
+++ b/builder/objcopy.go
@@ -2,7 +2,7 @@ package builder
 
 import (
 	"debug/elf"
-	"io/ioutil"
+	"io"
 	"os"
 	"sort"
 
@@ -87,7 +87,7 @@ func extractROM(path string) (uint64, []byte, error) {
 			// Pad the difference
 			rom = append(rom, make([]byte, diff)...)
 		}
-		data, err := ioutil.ReadAll(prog.Open())
+		data, err := io.ReadAll(prog.Open())
 		if err != nil {
 			return 0, nil, objcopyError{"failed to extract segment from ELF file: " + path, err}
 		}
diff --git a/builder/uf2.go b/builder/uf2.go
index 0d8696f8..62bae5c6 100644
--- a/builder/uf2.go
+++ b/builder/uf2.go
@@ -10,7 +10,7 @@ package builder
 import (
 	"bytes"
 	"encoding/binary"
-	"io/ioutil"
+	"os"
 	"strconv"
 )
 
@@ -26,7 +26,7 @@ func convertELFFileToUF2File(infile, outfile string, uf2FamilyID string) error {
 	if err != nil {
 		return err
 	}
-	return ioutil.WriteFile(outfile, output, 0644)
+	return os.WriteFile(outfile, output, 0644)
 }
 
 // convertBinToUF2 converts the binary bytes in input to UF2 formatted data.
diff --git a/goenv/version.go b/goenv/version.go
index c67e56da..910437e0 100644
--- a/goenv/version.go
+++ b/goenv/version.go
@@ -4,7 +4,7 @@ import (
 	"errors"
 	"fmt"
 	"io"
-	"io/ioutil"
+	"os"
 	"path/filepath"
 	"regexp"
 	"strings"
@@ -54,10 +54,10 @@ func GetGorootVersion(goroot string) (major, minor int, err error) {
 // toolchain for the given GOROOT path. It is usually of the form `go1.x.y` but
 // can have some variations (for beta releases, for example).
 func GorootVersionString(goroot string) (string, error) {
-	if data, err := ioutil.ReadFile(filepath.Join(goroot, "VERSION")); err == nil {
+	if data, err := os.ReadFile(filepath.Join(goroot, "VERSION")); err == nil {
 		return string(data), nil
 
-	} else if data, err := ioutil.ReadFile(filepath.Join(
+	} else if data, err := os.ReadFile(filepath.Join(
 		goroot, "src", "internal", "buildcfg", "zbootstrap.go")); err == nil {
 
 		r := regexp.MustCompile("const version = `(.*)`")
diff --git a/loader/goroot.go b/loader/goroot.go
index a012fc19..5039ed29 100644
--- a/loader/goroot.go
+++ b/loader/goroot.go
@@ -83,7 +83,7 @@ func GetCachedGoroot(config *compileopts.Config) (string, error) {
 	}
 
 	// Create a temporary directory to construct the goroot within.
-	tmpgoroot, err := ioutil.TempDir(goenv.Get("GOCACHE"), cachedGorootName+".tmp")
+	tmpgoroot, err := os.MkdirTemp(goenv.Get("GOCACHE"), cachedGorootName+".tmp")
 	if err != nil {
 		return "", err
 	}
diff --git a/loader/loader.go b/loader/loader.go
index 730eb701..6f49982d 100644
--- a/loader/loader.go
+++ b/loader/loader.go
@@ -13,7 +13,6 @@ import (
 	"go/token"
 	"go/types"
 	"io"
-	"io/ioutil"
 	"os"
 	"os/exec"
 	"path"
@@ -335,7 +334,7 @@ func (p *Package) OriginalDir() string {
 // parseFile is a wrapper around parser.ParseFile.
 func (p *Package) parseFile(path string, mode parser.Mode) (*ast.File, error) {
 	originalPath := p.program.getOriginalPath(path)
-	data, err := ioutil.ReadFile(path)
+	data, err := os.ReadFile(path)
 	if err != nil {
 		return nil, err
 	}
diff --git a/main.go b/main.go
index fc3822b1..05dc56d1 100644
--- a/main.go
+++ b/main.go
@@ -251,7 +251,7 @@ func Test(pkgName string, stdout, stderr io.Writer, options *compileopts.Options
 			}
 
 			// create a new temp directory just for this run, announce it to os.TempDir() via TMPDIR
-			tmpdir, err := ioutil.TempDir("", "tinygotmp")
+			tmpdir, err := os.MkdirTemp("", "tinygotmp")
 			if err != nil {
 				return fmt.Errorf("failed to create temporary directory: %w", err)
 			}
@@ -1467,7 +1467,7 @@ func main() {
 			fmt.Fprintf(os.Stderr, "Unknown library: %s\n", name)
 			os.Exit(1)
 		}
-		tmpdir, err := ioutil.TempDir("", "tinygo*")
+		tmpdir, err := os.MkdirTemp("", "tinygo*")
 		if err != nil {
 			handleCompilerError(err)
 		}
diff --git a/testdata/filesystem.go b/testdata/filesystem.go
index 1f561ba8..3825d618 100644
--- a/testdata/filesystem.go
+++ b/testdata/filesystem.go
@@ -1,7 +1,7 @@
 package main
 
 import (
-	"io/ioutil"
+	"io"
 	"os"
 )
 
@@ -28,7 +28,7 @@ func main() {
 		}
 	}()
 
-	data, err := ioutil.ReadAll(f)
+	data, err := io.ReadAll(f)
 	if err != nil {
 		panic(err)
 	}