diff --git a/proto/ignition/msgs/odometry_with_covariance.proto b/proto/ignition/msgs/odometry_with_covariance.proto
new file mode 100644
index 00000000..e68f4d3f
--- /dev/null
+++ b/proto/ignition/msgs/odometry_with_covariance.proto
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2022 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+*/
+syntax = "proto3";
+package ignition.msgs;
+option java_package = "com.ignition.msgs";
+option java_outer_classname = "OdometryWithCovarianceProtos";
+
+/// \ingroup ignition.msgs
+/// \interface OdometryWithCovariance
+/// \brief Message for odometry with covariance
+
+import "ignition/msgs/header.proto";
+import "ignition/msgs/pose_with_covariance.proto";
+import "ignition/msgs/twist_with_covariance.proto";
+
+message OdometryWithCovariance
+{
+  /// \brief Optional header data.
+  Header header                             = 1;
+
+  /// \brief Estimated pose.
+  PoseWithCovariance pose_with_covariance   = 2;
+
+  /// \brief Estimated linear and angular velocities.
+  TwistWithCovariance twist_with_covariance = 3;
+}
diff --git a/proto/ignition/msgs/pose_with_covariance.proto b/proto/ignition/msgs/pose_with_covariance.proto
new file mode 100644
index 00000000..1e8b0fc0
--- /dev/null
+++ b/proto/ignition/msgs/pose_with_covariance.proto
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2022 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+*/
+
+syntax = "proto3";
+package ignition.msgs;
+option java_package = "com.ignition.msgs";
+option java_outer_classname = "PoseWithCovarianceProtos";
+
+/// \ingroup ignition.msgs
+/// \interface PoseWithCovariance
+/// \brief Message with pose and a covariance matrix
+
+import "ignition/msgs/float_v.proto";
+import "ignition/msgs/pose.proto";
+
+message PoseWithCovariance
+{
+  /// \brief Pose message.
+  Pose pose          = 1;
+
+  /// \brief Row-major representation of the 6x6 covariance matrix
+  /// The orientation parameters use a fixed-axis representation.
+  /// In order, the parameters are:
+  /// (x, y, z, rotation about X axis, rotation about Y axis, rotation about Z axis)
+  Float_V covariance = 2;
+}
diff --git a/proto/ignition/msgs/twist.proto b/proto/ignition/msgs/twist.proto
index c80becf5..9c247aca 100644
--- a/proto/ignition/msgs/twist.proto
+++ b/proto/ignition/msgs/twist.proto
@@ -32,7 +32,7 @@ message Twist
   /// \brief Optional header data.
   Header header          = 1;
 
-  /// \brief Lnear velocity in 3d space.
+  /// \brief Linear velocity in 3d space.
   Vector3d linear        = 2;
 
   /// \brief Angular velocity in 3d space.
diff --git a/proto/ignition/msgs/twist_with_covariance.proto b/proto/ignition/msgs/twist_with_covariance.proto
new file mode 100644
index 00000000..5daf37c8
--- /dev/null
+++ b/proto/ignition/msgs/twist_with_covariance.proto
@@ -0,0 +1,40 @@
+/*
+ * Copyright (C) 2022 Open Source Robotics Foundation
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ *
+*/
+
+syntax = "proto3";
+package ignition.msgs;
+option java_package = "com.ignition.msgs";
+option java_outer_classname = "TwistWithCovarianceProtos";
+
+/// \ingroup ignition.msgs
+/// \interface TwistWithCovariance
+/// \brief Message with twist and a covariance matrix
+
+import "ignition/msgs/float_v.proto";
+import "ignition/msgs/twist.proto";
+
+message TwistWithCovariance
+{
+  /// \brief Twist message.
+  Twist twist        = 1;
+
+  /// \brief Row-major representation of the 6x6 covariance matrix
+  /// The orientation parameters use a fixed-axis representation.
+  /// In order, the parameters are:
+  /// (x, y, z, rotation about X axis, rotation about Y axis, rotation about Z axis)
+  Float_V covariance = 2;
+}