diff --git a/change-notes/2021-02-10-yaml.md b/change-notes/2021-02-10-yaml.md
new file mode 100644
index 00000000000..3a23f42a0f5
--- /dev/null
+++ b/change-notes/2021-02-10-yaml.md
@@ -0,0 +1,2 @@
+lgtm,codescanning
+* Added support for the [gopkg.in/yaml](https://pkg.go.dev/gopkg.in/yaml.v3) package, which may lead to more results from the security queries.
diff --git a/ql/src/go.qll b/ql/src/go.qll
index 6cfb2e5264c..1ef249783a4 100644
--- a/ql/src/go.qll
+++ b/ql/src/go.qll
@@ -58,5 +58,6 @@ import semmle.go.frameworks.Testing
 import semmle.go.frameworks.WebSocket
 import semmle.go.frameworks.XNetHtml
 import semmle.go.frameworks.XPath
+import semmle.go.frameworks.Yaml
 import semmle.go.frameworks.Zap
 import semmle.go.security.FlowSources
diff --git a/ql/src/semmle/go/frameworks/Yaml.qll b/ql/src/semmle/go/frameworks/Yaml.qll
new file mode 100644
index 00000000000..b661021f573
--- /dev/null
+++ b/ql/src/semmle/go/frameworks/Yaml.qll
@@ -0,0 +1,70 @@
+/**
+ * Provides classes for working with the [gopkg.in/yaml](https://pkg.go.dev/gopkg.in/yaml.v3) package.
+ */
+
+import go
+
+/**
+ * Provides classes for working with the [gopkg.in/yaml](https://pkg.go.dev/gopkg.in/yaml.v3) package.
+ */
+module Yaml {
+  /** Gets a package path for the Yaml package. */
+  bindingset[result]
+  string packagePath() { result = package("gopkg.in/yaml", "") }
+
+  private class MarshalFunction extends TaintTracking::FunctionModel, MarshalingFunction::Range {
+    MarshalFunction() { this.hasQualifiedName(packagePath(), "Marshal") }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = this.getAnInput() and output = this.getOutput()
+    }
+
+    override DataFlow::FunctionInput getAnInput() { result.isParameter(0) }
+
+    override DataFlow::FunctionOutput getOutput() { result.isResult(0) }
+
+    override string getFormat() { result = "yaml" }
+  }
+
+  private class UnmarshalFunction extends TaintTracking::FunctionModel, UnmarshalingFunction::Range {
+    UnmarshalFunction() { this.hasQualifiedName(packagePath(), ["Unmarshal", "UnmarshalStrict"]) }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = this.getAnInput() and output = this.getOutput()
+    }
+
+    override DataFlow::FunctionInput getAnInput() { result.isParameter(0) }
+
+    override DataFlow::FunctionOutput getOutput() { result.isParameter(1) }
+
+    override string getFormat() { result = "yaml" }
+  }
+
+  private class FunctionModels extends TaintTracking::FunctionModel {
+    FunctionInput inp;
+    FunctionOutput outp;
+
+    FunctionModels() {
+      this.hasQualifiedName(packagePath(), "NewDecoder") and
+      (inp.isParameter(0) and outp.isResult())
+      or
+      this.hasQualifiedName(packagePath(), "NewEncoder") and
+      (inp.isResult() and outp.isParameter(0))
+      or
+      exists(Method m | this = m |
+        m.hasQualifiedName(packagePath(), ["Decoder", "Node"], "Decode") and
+        (inp.isReceiver() and outp.isParameter(0))
+        or
+        m.hasQualifiedName(packagePath(), ["Encoder", "Node"], "Encode") and
+        (inp.isParameter(0) and outp.isReceiver())
+        or
+        m.hasQualifiedName(packagePath(), "Node", "SetString") and
+        (inp.isParameter(0) and outp.isReceiver())
+      )
+    }
+
+    override predicate hasTaintFlow(FunctionInput input, FunctionOutput output) {
+      input = inp and output = outp
+    }
+  }
+}
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/go.mod b/ql/test/library-tests/semmle/go/frameworks/Yaml/go.mod
new file mode 100644
index 00000000000..2604133f64c
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/Yaml/go.mod
@@ -0,0 +1,9 @@
+module codeql-go-tests/frameworks/Yaml
+
+go 1.15
+
+require (
+	gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0
+	gopkg.in/yaml.v2 v2.4.0
+	gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
+)
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/tests.expected b/ql/test/library-tests/semmle/go/frameworks/Yaml/tests.expected
new file mode 100644
index 00000000000..e69de29bb2d
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/tests.ql b/ql/test/library-tests/semmle/go/frameworks/Yaml/tests.ql
new file mode 100644
index 00000000000..9c76068a9a0
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/Yaml/tests.ql
@@ -0,0 +1,49 @@
+import go
+import TestUtilities.InlineExpectationsTest
+
+class TaintFunctionModelTest extends InlineExpectationsTest {
+  TaintFunctionModelTest() { this = "TaintFunctionModelTest" }
+
+  override string getARelevantTag() { result = "ttfnmodelstep" }
+
+  override predicate hasActualResult(string file, int line, string element, string tag, string value) {
+    tag = "ttfnmodelstep" and
+    exists(TaintTracking::FunctionModel model, DataFlow::CallNode call | call = model.getACall() |
+      call.hasLocationInfo(file, line, _, _, _) and
+      element = call.toString() and
+      value = model.getAnInputNode(call) + " -> " + model.getAnOutputNode(call)
+    )
+  }
+}
+
+class MarshalerTest extends InlineExpectationsTest {
+  MarshalerTest() { this = "MarshalerTest" }
+
+  override string getARelevantTag() { result = "marshaler" }
+
+  override predicate hasActualResult(string file, int line, string element, string tag, string value) {
+    tag = "marshaler" and
+    exists(MarshalingFunction m, DataFlow::CallNode call | call = m.getACall() |
+      call.hasLocationInfo(file, line, _, _, _) and
+      element = call.toString() and
+      value =
+        m.getFormat() + ": " + m.getAnInput().getNode(call) + " -> " + m.getOutput().getNode(call)
+    )
+  }
+}
+
+class UnmarshalerTest extends InlineExpectationsTest {
+  UnmarshalerTest() { this = "UnmarshalerTest" }
+
+  override string getARelevantTag() { result = "unmarshaler" }
+
+  override predicate hasActualResult(string file, int line, string element, string tag, string value) {
+    tag = "unmarshaler" and
+    exists(UnmarshalingFunction m, DataFlow::CallNode call | call = m.getACall() |
+      call.hasLocationInfo(file, line, _, _, _) and
+      element = call.toString() and
+      value =
+        m.getFormat() + ": " + m.getAnInput().getNode(call) + " -> " + m.getOutput().getNode(call)
+    )
+  }
+}
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v1/stub.go b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v1/stub.go
new file mode 100644
index 00000000000..c5dd4d66b9e
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v1/stub.go
@@ -0,0 +1,16 @@
+// Code generated by depstubber. DO NOT EDIT.
+// This is a simple stub for gopkg.in/yaml.v1, strictly for use in testing.
+
+// See the LICENSE file for information about the licensing of the original library.
+// Source: gopkg.in/yaml.v1 (exports: ; functions: Marshal,Unmarshal)
+
+// Package yaml is a stub of gopkg.in/yaml.v1, generated by depstubber.
+package yaml
+
+func Marshal(_ interface{}) ([]byte, error) {
+	return nil, nil
+}
+
+func Unmarshal(_ []byte, _ interface{}) error {
+	return nil
+}
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v2/stub.go b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v2/stub.go
new file mode 100644
index 00000000000..1e9fb9731bb
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v2/stub.go
@@ -0,0 +1,50 @@
+// Code generated by depstubber. DO NOT EDIT.
+// This is a simple stub for gopkg.in/yaml.v2, strictly for use in testing.
+
+// See the LICENSE file for information about the licensing of the original library.
+// Source: gopkg.in/yaml.v2 (exports: ; functions: Marshal,NewDecoder,NewEncoder,Unmarshal,UnmarshalStrict)
+
+// Package yaml is a stub of gopkg.in/yaml.v2, generated by depstubber.
+package yaml
+
+import (
+	io "io"
+)
+
+type Decoder struct{}
+
+func (_ *Decoder) Decode(_ interface{}) error {
+	return nil
+}
+
+func (_ *Decoder) SetStrict(_ bool) {}
+
+type Encoder struct{}
+
+func (_ *Encoder) Close() error {
+	return nil
+}
+
+func (_ *Encoder) Encode(_ interface{}) error {
+	return nil
+}
+
+func Marshal(_ interface{}) ([]byte, error) {
+	return nil, nil
+}
+
+func NewDecoder(_ io.Reader) *Decoder {
+	return nil
+}
+
+func NewEncoder(_ io.Writer) *Encoder {
+	return nil
+}
+
+func Unmarshal(_ []byte, _ interface{}) error {
+	return nil
+}
+
+func UnmarshalStrict(_ []byte, _ interface{}) error {
+	return nil
+}
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v3/stub.go b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v3/stub.go
new file mode 100644
index 00000000000..8578c981c2f
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/gopkg.in/yaml.v3/stub.go
@@ -0,0 +1,89 @@
+// Code generated by depstubber. DO NOT EDIT.
+// This is a simple stub for gopkg.in/yaml.v3, strictly for use in testing.
+
+// See the LICENSE file for information about the licensing of the original library.
+// Source: gopkg.in/yaml.v3 (exports: Node; functions: Marshal,NewDecoder,NewEncoder,Unmarshal)
+
+// Package yaml is a stub of gopkg.in/yaml.v3, generated by depstubber.
+package yaml
+
+import (
+	io "io"
+)
+
+type Decoder struct{}
+
+func (_ *Decoder) Decode(_ interface{}) error {
+	return nil
+}
+
+func (_ *Decoder) KnownFields(_ bool) {}
+
+type Encoder struct{}
+
+func (_ *Encoder) Close() error {
+	return nil
+}
+
+func (_ *Encoder) Encode(_ interface{}) error {
+	return nil
+}
+
+func (_ *Encoder) SetIndent(_ int) {}
+
+type Kind uint32
+
+func Marshal(_ interface{}) ([]byte, error) {
+	return nil, nil
+}
+
+func NewDecoder(_ io.Reader) *Decoder {
+	return nil
+}
+
+func NewEncoder(_ io.Writer) *Encoder {
+	return nil
+}
+
+type Node struct {
+	Kind        Kind
+	Style       Style
+	Tag         string
+	Value       string
+	Anchor      string
+	Alias       *Node
+	Content     []*Node
+	HeadComment string
+	LineComment string
+	FootComment string
+	Line        int
+	Column      int
+}
+
+func (_ *Node) Decode(_ interface{}) error {
+	return nil
+}
+
+func (_ *Node) Encode(_ interface{}) error {
+	return nil
+}
+
+func (_ *Node) IsZero() bool {
+	return false
+}
+
+func (_ *Node) LongTag() string {
+	return ""
+}
+
+func (_ *Node) SetString(_ string) {}
+
+func (_ *Node) ShortTag() string {
+	return ""
+}
+
+type Style uint32
+
+func Unmarshal(_ []byte, _ interface{}) error {
+	return nil
+}
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/modules.txt b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/modules.txt
new file mode 100644
index 00000000000..cf210e65d86
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/Yaml/vendor/modules.txt
@@ -0,0 +1,9 @@
+# gopkg.in/yaml.v1 v1.0.0-20140924161607-9f9df34309c0
+## explicit
+gopkg.in/yaml.v1
+# gopkg.in/yaml.v2 v2.4.0
+## explicit
+gopkg.in/yaml.v2
+# gopkg.in/yaml.v3 v3.0.0-20210107192922-496545a6307b
+## explicit
+gopkg.in/yaml.v3
diff --git a/ql/test/library-tests/semmle/go/frameworks/Yaml/yaml.go b/ql/test/library-tests/semmle/go/frameworks/Yaml/yaml.go
new file mode 100644
index 00000000000..d2796eb9997
--- /dev/null
+++ b/ql/test/library-tests/semmle/go/frameworks/Yaml/yaml.go
@@ -0,0 +1,41 @@
+package main
+
+import (
+	yaml1 "gopkg.in/yaml.v1"
+	yaml2 "gopkg.in/yaml.v2"
+	yaml3 "gopkg.in/yaml.v3"
+	"io"
+)
+
+func main() {
+	var in, out interface{}
+	var inb []byte
+
+	out, _ = yaml1.Marshal(in) // $marshaler=yaml: in -> ... = ...[0] $ttfnmodelstep=in -> ... = ...[0]
+	yaml1.Unmarshal(inb, out)  // $unmarshaler=yaml: inb -> definition of out $ttfnmodelstep=inb -> definition of out
+
+	out, _ = yaml2.Marshal(in)      // $marshaler=yaml: in -> ... = ...[0] $ttfnmodelstep=in -> ... = ...[0]
+	yaml2.Unmarshal(inb, out)       // $unmarshaler=yaml: inb -> definition of out $ttfnmodelstep=inb -> definition of out
+	yaml2.UnmarshalStrict(inb, out) // $unmarshaler=yaml: inb -> definition of out $ttfnmodelstep=inb -> definition of out
+
+	var r io.Reader
+	d := yaml2.NewDecoder(r) // $ttfnmodelstep=r -> call to NewDecoder
+	d.Decode(out)            // $ttfnmodelstep=d -> definition of out
+
+	var w io.Writer
+	e := yaml2.NewEncoder(w) // $ttfnmodelstep=definition of e -> definition of w
+	e.Encode(in)             // $ttfnmodelstep=in -> definition of e
+
+	out, _ = yaml3.Marshal(in) // $marshaler=yaml: in -> ... = ...[0] $ttfnmodelstep=in -> ... = ...[0]
+	yaml3.Unmarshal(inb, out)  // $unmarshaler=yaml: inb -> definition of out $ttfnmodelstep=inb -> definition of out
+
+	d1 := yaml3.NewDecoder(r) // $ttfnmodelstep=r -> call to NewDecoder
+	d1.Decode(out)            // $ttfnmodelstep=d1 -> definition of out
+
+	e1 := yaml3.NewEncoder(w) // $ttfnmodelstep=definition of e1 -> definition of w
+	e1.Encode(in)             // $ttfnmodelstep=in -> definition of e1
+
+	var n1 yaml3.Node
+	n1.Decode(out) // $ttfnmodelstep=n1 -> definition of out
+	n1.Encode(in)  // $ttfnmodelstep=in -> definition of n1
+}