diff --git a/cpp/CMakeLists.txt b/cpp/CMakeLists.txt
index 6d701079b48..e7d332b2f49 100644
--- a/cpp/CMakeLists.txt
+++ b/cpp/CMakeLists.txt
@@ -528,6 +528,7 @@ set(ARROW_SRCS
   src/arrow/ipc/metadata-internal.cc
 
   src/arrow/types/construct.cc
+  src/arrow/types/decimal.cc
   src/arrow/types/json.cc
   src/arrow/types/list.cc
   src/arrow/types/primitive.cc
diff --git a/cpp/src/arrow/types/decimal.cc b/cpp/src/arrow/types/decimal.cc
new file mode 100644
index 00000000000..f120c1a9dfd
--- /dev/null
+++ b/cpp/src/arrow/types/decimal.cc
@@ -0,0 +1,32 @@
+// Licensed to the Apache Software Foundation (ASF) under one
+// or more contributor license agreements.  See the NOTICE file
+// distributed with this work for additional information
+// regarding copyright ownership.  The ASF licenses this file
+// to you 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.
+
+#include "arrow/types/decimal.h"
+
+#include <sstream>
+#include <string>
+
+namespace arrow {
+
+std::string DecimalType::ToString() const {
+  std::stringstream s;
+  s << "decimal(" << precision << ", " << scale << ")";
+  return s.str();
+}
+
+} // namespace arrow
+
diff --git a/cpp/src/arrow/types/decimal.h b/cpp/src/arrow/types/decimal.h
index 464c3ff8da9..26243b42b0e 100644
--- a/cpp/src/arrow/types/decimal.h
+++ b/cpp/src/arrow/types/decimal.h
@@ -18,13 +18,24 @@
 #ifndef ARROW_TYPES_DECIMAL_H
 #define ARROW_TYPES_DECIMAL_H
 
+#include <string>
+
 #include "arrow/type.h"
 
 namespace arrow {
 
 struct DecimalType : public DataType {
+  explicit DecimalType(int precision_, int scale_)
+      : DataType(Type::DECIMAL), precision(precision_),
+        scale(scale_) { }
   int precision;
   int scale;
+
+  static char const *name() {
+    return "decimal";
+  }
+
+  std::string ToString() const override;
 };
 
 } // namespace arrow