diff --git a/internal/lsp/cmd/cmd_test.go b/internal/lsp/cmd/cmd_test.go
index 8863145..c1a882f 100644
--- a/internal/lsp/cmd/cmd_test.go
+++ b/internal/lsp/cmd/cmd_test.go
@@ -49,6 +49,11 @@
 func (r *runner) Highlight(t *testing.T, data tests.Highlights) {
 	//TODO: add command line highlight tests when it works
 }
+
+func (r *runner) Reference(t *testing.T, data tests.References) {
+	//TODO: add command line references tests when it works
+}
+
 func (r *runner) Symbol(t *testing.T, data tests.Symbols) {
 	//TODO: add command line symbol tests when it works
 }
diff --git a/internal/lsp/general.go b/internal/lsp/general.go
index 0964de7..92e28a5 100644
--- a/internal/lsp/general.go
+++ b/internal/lsp/general.go
@@ -69,6 +69,7 @@
 			HoverProvider:              true,
 			DocumentHighlightProvider:  true,
 			DocumentLinkProvider:       &protocol.DocumentLinkOptions{},
+			ReferencesProvider:         true,
 			SignatureHelpProvider: &protocol.SignatureHelpOptions{
 				TriggerCharacters: []string{"(", ","},
 			},
diff --git a/internal/lsp/lsp_test.go b/internal/lsp/lsp_test.go
index 2548b46..a7d12b0 100644
--- a/internal/lsp/lsp_test.go
+++ b/internal/lsp/lsp_test.go
@@ -460,6 +460,48 @@
 	}
 }
 
+func (r *runner) Reference(t *testing.T, data tests.References) {
+	for src, itemList := range data {
+		sm, err := r.mapper(src.URI())
+		if err != nil {
+			t.Fatal(err)
+		}
+		loc, err := sm.Location(src)
+		if err != nil {
+			t.Fatalf("failed for %v: %v", src, err)
+		}
+
+		want := make(map[protocol.Location]bool)
+		for _, pos := range itemList {
+			loc, err := sm.Location(pos)
+			if err != nil {
+				t.Fatalf("failed for %v: %v", src, err)
+			}
+			want[loc] = true
+		}
+
+		params := &protocol.ReferenceParams{
+			TextDocumentPositionParams: protocol.TextDocumentPositionParams{
+				TextDocument: protocol.TextDocumentIdentifier{URI: loc.URI},
+				Position:     loc.Range.Start,
+			},
+		}
+		got, err := r.server.References(context.Background(), params)
+		if err != nil {
+			t.Fatalf("failed for %v: %v", src, err)
+		}
+
+		if len(got) != len(itemList) {
+			t.Errorf("references failed: different lengths got %v want %v", len(got), len(itemList))
+		}
+		for _, loc := range got {
+			if !want[loc] {
+				t.Errorf("references failed: incorrect references got %v want %v", got, want)
+			}
+		}
+	}
+}
+
 func (r *runner) Symbol(t *testing.T, data tests.Symbols) {
 	for uri, expectedSymbols := range data {
 		params := &protocol.DocumentSymbolParams{
diff --git a/internal/lsp/references.go b/internal/lsp/references.go
new file mode 100644
index 0000000..2786244
--- /dev/null
+++ b/internal/lsp/references.go
@@ -0,0 +1,56 @@
+package lsp
+
+import (
+	"context"
+
+	"golang.org/x/tools/internal/lsp/protocol"
+	"golang.org/x/tools/internal/lsp/source"
+	"golang.org/x/tools/internal/span"
+)
+
+func (s *Server) references(ctx context.Context, params *protocol.ReferenceParams) ([]protocol.Location, error) {
+	uri := span.NewURI(params.TextDocument.URI)
+	view := s.session.ViewOf(uri)
+	f, m, err := getGoFile(ctx, view, uri)
+	if err != nil {
+		return nil, err
+	}
+	spn, err := m.PointSpan(params.Position)
+	if err != nil {
+		return nil, err
+	}
+	rng, err := spn.Range(m.Converter)
+	if err != nil {
+		return nil, err
+	}
+
+	// Find all references to the identifier at the position.
+	ident, err := source.Identifier(ctx, view, f, rng.Start)
+	if err != nil {
+		return nil, err
+	}
+	references, err := ident.References(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	// Get the location of each reference to return as the result.
+	locations := make([]protocol.Location, 0, len(references))
+	for _, ref := range references {
+		refSpan, err := ref.Range.Span()
+		if err != nil {
+			return nil, err
+		}
+		_, refM, err := getSourceFile(ctx, view, refSpan.URI())
+		if err != nil {
+			return nil, err
+		}
+		loc, err := refM.Location(refSpan)
+		if err != nil {
+			return nil, err
+		}
+
+		locations = append(locations, loc)
+	}
+	return locations, nil
+}
diff --git a/internal/lsp/server.go b/internal/lsp/server.go
index 13bcaef..121cc13 100644
--- a/internal/lsp/server.go
+++ b/internal/lsp/server.go
@@ -186,8 +186,8 @@
 	return nil, notImplemented("Implementation")
 }
 
-func (s *Server) References(context.Context, *protocol.ReferenceParams) ([]protocol.Location, error) {
-	return nil, notImplemented("References")
+func (s *Server) References(ctx context.Context, params *protocol.ReferenceParams) ([]protocol.Location, error) {
+	return s.references(ctx, params)
 }
 
 func (s *Server) DocumentHighlight(ctx context.Context, params *protocol.TextDocumentPositionParams) ([]protocol.DocumentHighlight, error) {
diff --git a/internal/lsp/source/references.go b/internal/lsp/source/references.go
new file mode 100644
index 0000000..8a3ae73
--- /dev/null
+++ b/internal/lsp/source/references.go
@@ -0,0 +1,56 @@
+package source
+
+import (
+	"context"
+	"fmt"
+	"go/ast"
+
+	"golang.org/x/tools/internal/span"
+)
+
+// ReferenceInfo holds information about reference to an identifier in Go source.
+type ReferenceInfo struct {
+	Name  string
+	Range span.Range
+	ident *ast.Ident
+}
+
+// References returns a list of references for a given identifier within a package.
+func (i *IdentifierInfo) References(ctx context.Context) ([]*ReferenceInfo, error) {
+	pkg := i.File.GetPackage(ctx)
+	if pkg == nil || pkg.IsIllTyped() {
+		return nil, fmt.Errorf("package for %s is ill typed", i.File.URI())
+	}
+	pkgInfo := pkg.GetTypesInfo()
+	if pkgInfo == nil {
+		return nil, fmt.Errorf("package %s has no types info", pkg.PkgPath())
+	}
+
+	// If the object declaration is nil, assume it is an import spec and do not look for references.
+	declObj := i.decl.obj
+	if declObj == nil {
+		return []*ReferenceInfo{}, nil
+	}
+
+	var references []*ReferenceInfo
+	for ident, obj := range pkgInfo.Defs {
+		if obj == declObj {
+			references = append(references, &ReferenceInfo{
+				Name:  ident.Name,
+				Range: span.NewRange(i.File.FileSet(), ident.Pos(), ident.End()),
+				ident: ident,
+			})
+		}
+	}
+	for ident, obj := range pkgInfo.Uses {
+		if obj == declObj {
+			references = append(references, &ReferenceInfo{
+				Name:  ident.Name,
+				Range: span.NewRange(i.File.FileSet(), ident.Pos(), ident.End()),
+				ident: ident,
+			})
+		}
+	}
+
+	return references, nil
+}
diff --git a/internal/lsp/source/source_test.go b/internal/lsp/source/source_test.go
index 8135e1d..be9c0f6 100644
--- a/internal/lsp/source/source_test.go
+++ b/internal/lsp/source/source_test.go
@@ -417,6 +417,46 @@
 	}
 }
 
+func (r *runner) Reference(t *testing.T, data tests.References) {
+	ctx := context.Background()
+	for src, itemList := range data {
+		f, err := r.view.GetFile(ctx, src.URI())
+		if err != nil {
+			t.Fatalf("failed for %v: %v", src, err)
+		}
+
+		tok := f.GetToken(ctx)
+		pos := tok.Pos(src.Start().Offset())
+		ident, err := source.Identifier(ctx, r.view, f.(source.GoFile), pos)
+		if err != nil {
+			t.Fatalf("failed for %v: %v", src, err)
+		}
+
+		want := make(map[span.Span]bool)
+		for _, pos := range itemList {
+			want[pos] = true
+		}
+
+		got, err := ident.References(ctx)
+		if err != nil {
+			t.Fatalf("failed for %v: %v", src, err)
+		}
+
+		if len(got) != len(itemList) {
+			t.Errorf("references failed: different lengths got %v want %v", len(got), len(itemList))
+		}
+		for _, refInfo := range got {
+			refSpan, err := refInfo.Range.Span()
+			if err != nil {
+				t.Errorf("failed for %v item %v: %v", src, refInfo.Name, err)
+			}
+			if !want[refSpan] {
+				t.Errorf("references failed: incorrect references got %v want locations %v", got, want)
+			}
+		}
+	}
+}
+
 func (r *runner) Symbol(t *testing.T, data tests.Symbols) {
 	ctx := context.Background()
 	for uri, expectedSymbols := range data {
diff --git a/internal/lsp/testdata/foo/foo.go b/internal/lsp/testdata/foo/foo.go
index 0e33467..094623e 100644
--- a/internal/lsp/testdata/foo/foo.go
+++ b/internal/lsp/testdata/foo/foo.go
@@ -13,8 +13,8 @@
 }
 
 func _() {
-	var sFoo StructFoo           //@complete("t", StructFoo)
-	if x := sFoo; x.Value == 1 { //@complete("V", Value),typdef("sFoo", StructFoo)
+	var sFoo StructFoo           //@mark(sFoo1, "sFoo"),complete("t", StructFoo)
+	if x := sFoo; x.Value == 1 { //@mark(sFoo2, "sFoo"),complete("V", Value),typdef("sFoo", StructFoo),refs("sFo", sFoo1, sFoo2)
 		return
 	}
 }
@@ -22,7 +22,7 @@
 func _() {
 	shadowed := 123
 	{
-		shadowed := "hi" //@item(shadowed, "shadowed", "string", "var")
+		shadowed := "hi" //@item(shadowed, "shadowed", "string", "var"),refs("shadowed", shadowed)
 		sha              //@complete("a", shadowed)
 	}
 }
diff --git a/internal/lsp/tests/tests.go b/internal/lsp/tests/tests.go
index a8dc349..81f1a10 100644
--- a/internal/lsp/tests/tests.go
+++ b/internal/lsp/tests/tests.go
@@ -34,6 +34,7 @@
 	ExpectedDefinitionsCount       = 35
 	ExpectedTypeDefinitionsCount   = 2
 	ExpectedHighlightsCount        = 2
+	ExpectedReferencesCount        = 2
 	ExpectedSymbolsCount           = 1
 	ExpectedSignaturesCount        = 20
 	ExpectedLinksCount             = 2
@@ -56,6 +57,7 @@
 type Imports []span.Span
 type Definitions map[span.Span]Definition
 type Highlights map[string][]span.Span
+type References map[span.Span][]span.Span
 type Symbols map[span.URI][]source.Symbol
 type SymbolsChildren map[string][]source.Symbol
 type Signatures map[span.Span]source.SignatureInformation
@@ -72,6 +74,7 @@
 	Imports            Imports
 	Definitions        Definitions
 	Highlights         Highlights
+	References         References
 	Symbols            Symbols
 	symbolsChildren    SymbolsChildren
 	Signatures         Signatures
@@ -90,6 +93,7 @@
 	Import(*testing.T, Imports)
 	Definition(*testing.T, Definitions)
 	Highlight(*testing.T, Highlights)
+	Reference(*testing.T, References)
 	Symbol(*testing.T, Symbols)
 	SignatureHelp(*testing.T, Signatures)
 	Link(*testing.T, Links)
@@ -130,6 +134,7 @@
 		CompletionSnippets: make(CompletionSnippets),
 		Definitions:        make(Definitions),
 		Highlights:         make(Highlights),
+		References:         make(References),
 		Symbols:            make(Symbols),
 		symbolsChildren:    make(SymbolsChildren),
 		Signatures:         make(Signatures),
@@ -209,6 +214,7 @@
 		"typdef":    data.collectTypeDefinitions,
 		"hover":     data.collectHoverDefinitions,
 		"highlight": data.collectHighlights,
+		"refs":      data.collectReferences,
 		"symbol":    data.collectSymbols,
 		"signature": data.collectSignatures,
 		"snippet":   data.collectCompletionSnippets,
@@ -289,6 +295,14 @@
 		tests.Highlight(t, data.Highlights)
 	})
 
+	t.Run("References", func(t *testing.T) {
+		t.Helper()
+		if len(data.References) != ExpectedReferencesCount {
+			t.Errorf("got %v references expected %v", len(data.References), ExpectedReferencesCount)
+		}
+		tests.Reference(t, data.References)
+	})
+
 	t.Run("Symbols", func(t *testing.T) {
 		t.Helper()
 		if len(data.Symbols) != ExpectedSymbolsCount {
@@ -456,6 +470,10 @@
 	data.Highlights[name] = append(data.Highlights[name], rng)
 }
 
+func (data *Data) collectReferences(src span.Span, expected []span.Span) {
+	data.References[src] = expected
+}
+
 func (data *Data) collectSymbols(name string, spn span.Span, kind string, parentName string) {
 	sym := source.Symbol{
 		Name:          name,