diff --git a/src/os/rlimit.go b/src/os/rlimit.go
new file mode 100644
index 0000000000000..a89414d098bbd
--- /dev/null
+++ b/src/os/rlimit.go
@@ -0,0 +1,32 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || darwin || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+
+package os
+
+import "syscall"
+
+// Some systems set an artificially low soft limit on open file count, for compatibility
+// with code that uses select and its hard-coded maximum file descriptor
+// (limited by the size of fd_set).
+//
+// Go does not use select, so it should not be subject to these limits.
+// On some systems the limit is 256, which is very easy to run into,
+// even in simple programs like gofmt when they parallelize walking
+// a file tree.
+//
+// After a long discussion on go.dev/issue/46279, we decided the
+// best approach was for Go to raise the limit unconditionally for itself,
+// and then leave old software to set the limit back as needed.
+// Code that really wants Go to leave the limit alone can set the hard limit,
+// which Go of course has no choice but to respect.
+func init() {
+	var lim syscall.Rlimit
+	if err := syscall.Getrlimit(syscall.RLIMIT_NOFILE, &lim); err == nil && lim.Cur != lim.Max {
+		lim.Cur = lim.Max
+		adjustFileLimit(&lim)
+		syscall.Setrlimit(syscall.RLIMIT_NOFILE, &lim)
+	}
+}
diff --git a/src/os/rlimit_darwin.go b/src/os/rlimit_darwin.go
new file mode 100644
index 0000000000000..b28982a83a193
--- /dev/null
+++ b/src/os/rlimit_darwin.go
@@ -0,0 +1,22 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build darwin
+
+package os
+
+import "syscall"
+
+// adjustFileLimit adds per-OS limitations on the Rlimit used for RLIMIT_NOFILE. See rlimit.go.
+func adjustFileLimit(lim *syscall.Rlimit) {
+	// On older macOS, setrlimit(RLIMIT_NOFILE, lim) with lim.Cur = infinity fails.
+	// Set to the value of kern.maxfilesperproc instead.
+	n, err := syscall.SysctlUint32("kern.maxfilesperproc")
+	if err != nil {
+		return
+	}
+	if lim.Cur > uint64(n) {
+		lim.Cur = uint64(n)
+	}
+}
diff --git a/src/os/rlimit_stub.go b/src/os/rlimit_stub.go
new file mode 100644
index 0000000000000..cbe28400c5b47
--- /dev/null
+++ b/src/os/rlimit_stub.go
@@ -0,0 +1,12 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+//go:build aix || dragonfly || freebsd || linux || netbsd || openbsd || solaris
+
+package os
+
+import "syscall"
+
+// adjustFileLimit adds per-OS limitations on the Rlimit used for RLIMIT_NOFILE. See rlimit.go.
+func adjustFileLimit(lim *syscall.Rlimit) {}
diff --git a/src/os/rlimit_test.go b/src/os/rlimit_test.go
new file mode 100644
index 0000000000000..5859e682ea919
--- /dev/null
+++ b/src/os/rlimit_test.go
@@ -0,0 +1,37 @@
+// Copyright 2022 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package os_test
+
+import (
+	. "os"
+	"runtime"
+	"testing"
+)
+
+func TestOpenFileLimit(t *testing.T) {
+	if runtime.GOOS == "openbsd" && (runtime.GOARCH == "arm" || runtime.GOARCH == "arm64") {
+		t.Skip("broken on openbsd/arm and openbsd/arm64 builder - go.dev/issue/51713")
+	}
+
+	// For open file count,
+	// macOS sets the default soft limit to 256 and no hard limit.
+	// CentOS and Fedora set the default soft limit to 1024,
+	// with hard limits of 4096 and 524288, respectively.
+	// Check that we can open 1200 files, which proves
+	// that the rlimit is being raised appropriately on those systems.
+	var files []*File
+	for i := 0; i < 1200; i++ {
+		f, err := Open("rlimit.go")
+		if err != nil {
+			t.Error(err)
+			break
+		}
+		files = append(files, f)
+	}
+
+	for _, f := range files {
+		f.Close()
+	}
+}