Index: flang/include/flang/Optimizer/Builder/FIRBuilder.h
===================================================================
--- flang/include/flang/Optimizer/Builder/FIRBuilder.h
+++ flang/include/flang/Optimizer/Builder/FIRBuilder.h
@@ -560,6 +560,10 @@
 mlir::Value genCPtrOrCFunptrAddr(fir::FirOpBuilder &builder, mlir::Location loc,
                                  mlir::Value cPtr, mlir::Type ty);
 
+/// Get the C address value.
+mlir::Value genCPtrOrCFunptrValue(fir::FirOpBuilder &builder,
+                                  mlir::Location loc, mlir::Value cPtr);
+
 } // namespace fir::factory
 
 #endif // FORTRAN_OPTIMIZER_BUILDER_FIRBUILDER_H
Index: flang/lib/Lower/IntrinsicCall.cpp
===================================================================
--- flang/lib/Lower/IntrinsicCall.cpp
+++ flang/lib/Lower/IntrinsicCall.cpp
@@ -481,6 +481,10 @@
   fir::ExtendedValue genCount(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   void genCpuTime(llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genCshift(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
+  fir::ExtendedValue genCAssociatedCFunPtr(mlir::Type,
+                                           llvm::ArrayRef<fir::ExtendedValue>);
+  fir::ExtendedValue genCAssociatedCPtr(mlir::Type,
+                                        llvm::ArrayRef<fir::ExtendedValue>);
   void genCFPointer(llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genCFunLoc(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
   fir::ExtendedValue genCLoc(mlir::Type, llvm::ArrayRef<fir::ExtendedValue>);
@@ -731,6 +735,14 @@
     {"ble", &I::genBitwiseCompare<mlir::arith::CmpIPredicate::ule>},
     {"blt", &I::genBitwiseCompare<mlir::arith::CmpIPredicate::ult>},
     {"btest", &I::genBtest},
+    {"c_associated_c_funptr",
+     &I::genCAssociatedCFunPtr,
+     {{{"c_ptr_1", asValue}, {"c_ptr_2", asValue, handleDynamicOptional}}},
+     /*isElemental=*/false},
+    {"c_associated_c_ptr",
+     &I::genCAssociatedCPtr,
+     {{{"c_ptr_1", asValue}, {"c_ptr_2", asValue, handleDynamicOptional}}},
+     /*isElemental=*/false},
     {"c_f_pointer",
      &I::genCFPointer,
      {{{"cptr", asValue},
@@ -2611,16 +2623,50 @@
   return res;
 }
 
+/// C_ASSOCIATED
+static fir::ExtendedValue
+genCAssociated(fir::FirOpBuilder &builder, mlir::Location loc,
+               mlir::Type resultType, llvm::ArrayRef<fir::ExtendedValue> args) {
+  assert(args.size() == 2);
+  mlir::Value cPtr1 = fir::getBase(args[0]);
+  mlir::Value cPtrVal1 =
+      fir::factory::genCPtrOrCFunptrValue(builder, loc, cPtr1);
+  mlir::Value zero = builder.createIntegerConstant(loc, cPtrVal1.getType(), 0);
+  mlir::Value res = builder.create<mlir::arith::CmpIOp>(
+      loc, mlir::arith::CmpIPredicate::ne, cPtrVal1, zero);
+
+  if (isStaticallyPresent(args[1])) {
+    mlir::Value cPtr2 = fir::getBase(args[1]);
+    mlir::Value cPtrVal2 =
+        fir::factory::genCPtrOrCFunptrValue(builder, loc, cPtr2);
+    mlir::Value cmpVal = builder.create<mlir::arith::CmpIOp>(
+        loc, mlir::arith::CmpIPredicate::eq, cPtrVal1, cPtrVal2);
+    res = builder.create<mlir::arith::AndIOp>(loc, res, cmpVal);
+  }
+  return builder.createConvert(loc, resultType, res);
+}
+
+/// C_ASSOCIATED (C_FUNPTR [, C_FUNPTR])
+fir::ExtendedValue IntrinsicLibrary::genCAssociatedCFunPtr(
+    mlir::Type resultType, llvm::ArrayRef<fir::ExtendedValue> args) {
+  return genCAssociated(builder, loc, resultType, args);
+}
+
+/// C_ASSOCIATED (C_PTR [, C_PTR])
+fir::ExtendedValue
+IntrinsicLibrary::genCAssociatedCPtr(mlir::Type resultType,
+                                     llvm::ArrayRef<fir::ExtendedValue> args) {
+  return genCAssociated(builder, loc, resultType, args);
+}
+
 // C_F_POINTER
 void IntrinsicLibrary::genCFPointer(llvm::ArrayRef<fir::ExtendedValue> args) {
   assert(args.size() == 3);
   // Handle CPTR argument
   // Get the value of the C address or the result of a reference to C_LOC.
   mlir::Value cPtr = fir::getBase(args[0]);
-  mlir::Type cPtrTy = fir::unwrapRefType(cPtr.getType());
-  mlir::Value cPtrAddr =
-      fir::factory::genCPtrOrCFunptrAddr(builder, loc, cPtr, cPtrTy);
-  mlir::Value cPtrAddrVal = builder.create<fir::LoadOp>(loc, cPtrAddr);
+  mlir::Value cPtrAddrVal =
+      fir::factory::genCPtrOrCFunptrValue(builder, loc, cPtr);
 
   // Handle FPTR argument
   const auto *fPtr = args[1].getBoxOf<fir::MutableBoxValue>();
Index: flang/lib/Optimizer/Builder/FIRBuilder.cpp
===================================================================
--- flang/lib/Optimizer/Builder/FIRBuilder.cpp
+++ flang/lib/Optimizer/Builder/FIRBuilder.cpp
@@ -1317,3 +1317,12 @@
   return builder.create<fir::CoordinateOp>(loc, builder.getRefType(fieldTy),
                                            cPtr, field);
 }
+
+mlir::Value fir::factory::genCPtrOrCFunptrValue(fir::FirOpBuilder &builder,
+                                                mlir::Location loc,
+                                                mlir::Value cPtr) {
+  mlir::Type cPtrTy = fir::unwrapRefType(cPtr.getType());
+  mlir::Value cPtrAddr =
+      fir::factory::genCPtrOrCFunptrAddr(builder, loc, cPtr, cPtrTy);
+  return builder.create<fir::LoadOp>(loc, cPtrAddr);
+}
Index: flang/test/Lower/Intrinsics/c_associated.f90
===================================================================
--- /dev/null
+++ flang/test/Lower/Intrinsics/c_associated.f90
@@ -0,0 +1,78 @@
+! RUN: bbc -emit-fir %s -o - | FileCheck %s
+! RUN: %flang_fc1 -emit-fir %s -o - | FileCheck %s
+
+! Test intrinsic module procedure c_associated
+
+! CHECK-LABEL: func.func @_QPtest_1(
+! CHECK-SAME:                       %[[VAL_0:.*]]: !fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>> {fir.bindc_name = "cptr1"},
+! CHECK-SAME:                       %[[VAL_1:.*]]: !fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>> {fir.bindc_name = "cptr2"}) {
+! CHECK:         %[[VAL_2:.*]] = fir.alloca !fir.logical<4> {bindc_name = "z1", uniq_name = "_QFtest_1Ez1"}
+! CHECK:         %[[VAL_3:.*]] = fir.alloca !fir.logical<4> {bindc_name = "z2", uniq_name = "_QFtest_1Ez2"}
+! CHECK:         %[[VAL_4:.*]] = fir.field_index __address, !fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>
+! CHECK:         %[[VAL_5:.*]] = fir.coordinate_of %[[VAL_0]], %[[VAL_4]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
+! CHECK:         %[[VAL_6:.*]] = fir.load %[[VAL_5]] : !fir.ref<i64>
+! CHECK:         %[[VAL_7:.*]] = arith.constant 0 : i64
+! CHECK:         %[[VAL_8:.*]] = arith.cmpi ne, %[[VAL_6]], %[[VAL_7]] : i64
+! CHECK:         %[[VAL_9:.*]] = fir.convert %[[VAL_8]] : (i1) -> !fir.logical<4>
+! CHECK:         fir.store %[[VAL_9]] to %[[VAL_2]] : !fir.ref<!fir.logical<4>>
+! CHECK:         %[[VAL_10:.*]] = fir.field_index __address, !fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>
+! CHECK:         %[[VAL_11:.*]] = fir.coordinate_of %[[VAL_0]], %[[VAL_10]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
+! CHECK:         %[[VAL_12:.*]] = fir.load %[[VAL_11]] : !fir.ref<i64>
+! CHECK:         %[[VAL_13:.*]] = arith.constant 0 : i64
+! CHECK:         %[[VAL_14:.*]] = arith.cmpi ne, %[[VAL_12]], %[[VAL_13]] : i64
+! CHECK:         %[[VAL_15:.*]] = fir.field_index __address, !fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>
+! CHECK:         %[[VAL_16:.*]] = fir.coordinate_of %[[VAL_1]], %[[VAL_15]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_ptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
+! CHECK:         %[[VAL_17:.*]] = fir.load %[[VAL_16]] : !fir.ref<i64>
+! CHECK:         %[[VAL_18:.*]] = arith.cmpi eq, %[[VAL_12]], %[[VAL_17]] : i64
+! CHECK:         %[[VAL_19:.*]] = arith.andi %[[VAL_14]], %[[VAL_18]] : i1
+! CHECK:         %[[VAL_20:.*]] = fir.convert %[[VAL_19]] : (i1) -> !fir.logical<4>
+! CHECK:         fir.store %[[VAL_20]] to %[[VAL_3]] : !fir.ref<!fir.logical<4>>
+! CHECK:         return
+! CHECK:       }
+
+subroutine test_1(cptr1, cptr2)
+  use iso_c_binding
+  type(c_ptr) :: cptr1, cptr2
+  logical :: z1, z2
+
+  z1 = c_associated(cptr1)
+
+  z2 = c_associated(cptr1, cptr2)
+end
+
+! CHECK-LABEL: func.func @_QPtest_2(
+! CHECK-SAME:                       %[[VAL_0:.*]]: !fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>> {fir.bindc_name = "cptr1"},
+! CHECK-SAME:                       %[[VAL_1:.*]]: !fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>> {fir.bindc_name = "cptr2"}) {
+! CHECK:         %[[VAL_2:.*]] = fir.alloca !fir.logical<4> {bindc_name = "z1", uniq_name = "_QFtest_2Ez1"}
+! CHECK:         %[[VAL_3:.*]] = fir.alloca !fir.logical<4> {bindc_name = "z2", uniq_name = "_QFtest_2Ez2"}
+! CHECK:         %[[VAL_4:.*]] = fir.field_index __address, !fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>
+! CHECK:         %[[VAL_5:.*]] = fir.coordinate_of %[[VAL_0]], %[[VAL_4]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
+! CHECK:         %[[VAL_6:.*]] = fir.load %[[VAL_5]] : !fir.ref<i64>
+! CHECK:         %[[VAL_7:.*]] = arith.constant 0 : i64
+! CHECK:         %[[VAL_8:.*]] = arith.cmpi ne, %[[VAL_6]], %[[VAL_7]] : i64
+! CHECK:         %[[VAL_9:.*]] = fir.convert %[[VAL_8]] : (i1) -> !fir.logical<4>
+! CHECK:         fir.store %[[VAL_9]] to %[[VAL_2]] : !fir.ref<!fir.logical<4>>
+! CHECK:         %[[VAL_10:.*]] = fir.field_index __address, !fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>
+! CHECK:         %[[VAL_11:.*]] = fir.coordinate_of %[[VAL_0]], %[[VAL_10]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
+! CHECK:         %[[VAL_12:.*]] = fir.load %[[VAL_11]] : !fir.ref<i64>
+! CHECK:         %[[VAL_13:.*]] = arith.constant 0 : i64
+! CHECK:         %[[VAL_14:.*]] = arith.cmpi ne, %[[VAL_12]], %[[VAL_13]] : i64
+! CHECK:         %[[VAL_15:.*]] = fir.field_index __address, !fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>
+! CHECK:         %[[VAL_16:.*]] = fir.coordinate_of %[[VAL_1]], %[[VAL_15]] : (!fir.ref<!fir.type<_QM__fortran_builtinsT__builtin_c_funptr{__address:i64}>>, !fir.field) -> !fir.ref<i64>
+! CHECK:         %[[VAL_17:.*]] = fir.load %[[VAL_16]] : !fir.ref<i64>
+! CHECK:         %[[VAL_18:.*]] = arith.cmpi eq, %[[VAL_12]], %[[VAL_17]] : i64
+! CHECK:         %[[VAL_19:.*]] = arith.andi %[[VAL_14]], %[[VAL_18]] : i1
+! CHECK:         %[[VAL_20:.*]] = fir.convert %[[VAL_19]] : (i1) -> !fir.logical<4>
+! CHECK:         fir.store %[[VAL_20]] to %[[VAL_3]] : !fir.ref<!fir.logical<4>>
+! CHECK:         return
+! CHECK:       }
+
+subroutine test_2(cptr1, cptr2)
+  use iso_c_binding
+  type(c_funptr) :: cptr1, cptr2
+  logical :: z1, z2
+
+  z1 = c_associated(cptr1)
+
+  z2 = c_associated(cptr1, cptr2)
+end