diff --git a/flang/include/flang/Optimizer/Dialect/CMakeLists.txt b/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
--- a/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
+++ b/flang/include/flang/Optimizer/Dialect/CMakeLists.txt
@@ -12,6 +12,7 @@
 mlir_tablegen(FIROps.cpp.inc -gen-op-defs)
 mlir_tablegen(FIROpsTypes.h.inc --gen-typedef-decls)
 mlir_tablegen(FIROpsTypes.cpp.inc --gen-typedef-defs)
+add_mlir_interface(FortranVariableInterface)
 add_public_tablegen_target(FIROpsIncGen)
 
 set(LLVM_TARGET_DEFINITIONS CanonicalizationPatterns.td)
diff --git a/flang/include/flang/Optimizer/Dialect/FortranVariableInterface.h b/flang/include/flang/Optimizer/Dialect/FortranVariableInterface.h
new file mode 100644
--- /dev/null
+++ b/flang/include/flang/Optimizer/Dialect/FortranVariableInterface.h
@@ -0,0 +1,26 @@
+//===- FortranVariableInterface.h -------------------------------*- C++ -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file contains a set of interfaces for operations defining Fortran
+// variables.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRAN_OPTIMIZER_DIALECT_FORTRANVARIABLEINTERFACE_H
+#define FORTRAN_OPTIMIZER_DIALECT_FORTRANVARIABLEINTERFACE_H
+
+#include "flang/Optimizer/Dialect/FIRAttr.h"
+#include "flang/Optimizer/Dialect/FIRType.h"
+#include "mlir/IR/BuiltinTypes.h"
+#include "mlir/IR/OpDefinition.h"
+
+namespace fir {
+#include "flang/Optimizer/Dialect/FortranVariableInterface.h.inc"
+} // namespace fir
+
+#endif // FORTRAN_OPTIMIZER_DIALECT_FORTRANVARIABLEINTERFACE_H
diff --git a/flang/include/flang/Optimizer/Dialect/FortranVariableInterface.td b/flang/include/flang/Optimizer/Dialect/FortranVariableInterface.td
new file mode 100644
--- /dev/null
+++ b/flang/include/flang/Optimizer/Dialect/FortranVariableInterface.td
@@ -0,0 +1,124 @@
+//===- FortranVariableInterface.td -------------------------*- tablegen -*-===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines an interface for operations defining Fortran variables.
+//
+//===----------------------------------------------------------------------===//
+
+#ifndef FORTRANVARIABLEINTERFACE
+#define FORTRANVARIABLEINTERFACE
+
+include "mlir/IR/OpBase.td"
+
+
+def FortranVariableOpInterface : OpInterface<"FortranVariableOpInterface"> {
+  let description = [{
+    Interface for operations that create Fortran like variables in order to
+    query about all their Fortran properties.
+  }];
+
+  let methods = [
+    InterfaceMethod<
+      /*desc=*/"Get the address produced by the definition",
+      /*retTy=*/"mlir::Value",
+      /*methodName=*/"getBase",
+      /*args=*/(ins),
+      /*methodBody=*/[{}],
+      /*defaultImplementation=*/[{
+        ConcreteOp op = mlir::cast<ConcreteOp>(this->getOperation());
+        return op.getResult();
+      }]
+    >,
+    InterfaceMethod<
+      /*desc=*/"Get Fortran attributes",
+      /*retTy=*/"llvm::Optional<fir::FortranVariableFlagsEnum>",
+      /*methodName=*/"getFortranAttrs",
+      /*args=*/(ins),
+      /*methodBody=*/[{}],
+      /*defaultImplementation=*/[{
+        ConcreteOp op = mlir::cast<ConcreteOp>(this->getOperation());
+        return op.getFortran_attrs();
+      }]
+    >,
+    InterfaceMethod<
+      /*desc=*/"Get the shape of the variable",
+      /*retTy=*/"llvm::Optional<mlir::Value>",
+      /*methodName=*/"getShape",
+      /*args=*/(ins),
+      /*methodBody=*/[{}],
+      /*defaultImplementation=*/[{
+        ConcreteOp op = mlir::cast<ConcreteOp>(this->getOperation());
+        return op.getShape();
+      }]
+    >,
+    InterfaceMethod<
+      /*desc=*/"Get explicit type parameters of the variable",
+      /*retTy=*/"mlir::OperandRange",
+      /*methodName=*/"getExplicitTypeParams",
+      /*args=*/(ins),
+      /*methodBody=*/[{}],
+      /*defaultImplementation=*/[{
+        ConcreteOp op = mlir::cast<ConcreteOp>(this->getOperation());
+        return op.getTypeparams();
+      }]
+    >,
+  ];
+
+  let extraClassDeclaration = [{
+
+    /// Get the sequence type or scalar value type corresponding to this
+    /// variable.
+    mlir::Type getElementOrSequenceType() {
+      return fir::unwrapPassByRefType(getBase().getType());
+    }
+
+    /// Get the scalar value type corresponding to this variable.
+    mlir::Type getElementType() {
+      return fir::unwrapSequenceType(getElementOrSequenceType());
+    }
+
+    /// Is the variable an array ?
+    bool isArray() {
+      return getElementOrSequenceType().isa<fir::SequenceType>();
+    }
+
+    /// Is this variable a Fortran pointer ?
+    bool isPointer() {
+      auto attrs = getFortranAttrs();
+      return attrs && bitEnumContainsAny(*attrs,
+                        fir::FortranVariableFlagsEnum::pointer);
+    }
+
+    /// Is this variable a Fortran allocatable ?
+    bool isAllocatable() {
+      auto attrs = getFortranAttrs();
+      return attrs && bitEnumContainsAny(*attrs,
+                        fir::FortranVariableFlagsEnum::allocatable);
+    }
+
+    /// Is this a Fortran character variable ?
+    bool isCharacter() {
+      return getElementType().isa<fir::CharacterType>();
+    }
+
+    /// Is this a Fortran character variable with an explicit length ?
+    bool hasExplicitCharLen() {
+      return isCharacter() && !getExplicitTypeParams().empty();
+    }
+
+    /// Return the length of explicit length character variable.
+    mlir::Value getExplicitCharLen() {
+      assert(hasExplicitCharLen() && "must be an explicit length character");
+      return getExplicitTypeParams()[0];
+    }
+
+  }];
+
+}
+
+#endif  // FORTRANVARIABLEINTERFACE
diff --git a/flang/lib/Optimizer/Dialect/CMakeLists.txt b/flang/lib/Optimizer/Dialect/CMakeLists.txt
--- a/flang/lib/Optimizer/Dialect/CMakeLists.txt
+++ b/flang/lib/Optimizer/Dialect/CMakeLists.txt
@@ -3,6 +3,7 @@
   FIRDialect.cpp
   FIROps.cpp
   FIRType.cpp
+  FortranVariableInterface.cpp
   Inliner.cpp
 
   DEPENDS
diff --git a/flang/lib/Optimizer/Dialect/FortranVariableInterface.cpp b/flang/lib/Optimizer/Dialect/FortranVariableInterface.cpp
new file mode 100644
--- /dev/null
+++ b/flang/lib/Optimizer/Dialect/FortranVariableInterface.cpp
@@ -0,0 +1,17 @@
+//===-- FortranVariableInterface.cpp.cpp ----------------------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// Coding style: https://mlir.llvm.org/getting_started/DeveloperGuide/
+//
+//===----------------------------------------------------------------------===//
+
+#include "flang/Optimizer/Dialect/FortranVariableInterface.h"
+
+namespace fir {
+#include "flang/Optimizer/Dialect/FortranVariableInterface.cpp.inc"
+}