Index: flang/lib/Lower/OpenMP.cpp
===================================================================
--- flang/lib/Lower/OpenMP.cpp
+++ flang/lib/Lower/OpenMP.cpp
@@ -247,6 +247,7 @@
   mlir::omp::ClauseProcBindKindAttr procBindKindAttr;
   SmallVector<Value> allocateOperands, allocatorOperands;
   mlir::UnitAttr nowaitAttr;
+  mlir::Attribute simdClauseOperand;
 
   const auto &opClauseList =
       std::get<Fortran::parser::OmpClauseList>(beginBlockDirective.t);
@@ -292,6 +293,9 @@
                    &clause.u)) {
       // Privatisation clauses are handled elsewhere.
       continue;
+    } else if (std::get_if<Fortran::parser::OmpClause::Threads>(&clause.u)) {
+      // Nothing needs to be done for threads clause.
+      continue;
     } else {
       TODO(currentLocation, "OpenMP Block construct clauses");
     }
@@ -319,6 +323,10 @@
     auto singleOp = firOpBuilder.create<mlir::omp::SingleOp>(
         currentLocation, allocateOperands, allocatorOperands, nowaitAttr);
     createBodyOfOp<omp::SingleOp>(singleOp, converter, currentLocation);
+  } else if (blockDirective.v == llvm::omp::OMPD_ordered) {
+    auto orderedOp = firOpBuilder.create<mlir::omp::OrderedRegionOp>(
+        currentLocation, simdClauseOperand.dyn_cast_or_null<UnitAttr>());
+    createBodyOfOp<omp::OrderedRegionOp>(orderedOp, converter, currentLocation);
   } else {
     TODO(converter.getCurrentLocation(), "Unhandled block directive");
   }
Index: flang/test/Lower/OpenMP/omp-ordered-threads.f90
===================================================================
--- /dev/null
+++ flang/test/Lower/OpenMP/omp-ordered-threads.f90
@@ -0,0 +1,42 @@
+! This test checks lowering of OpenMP ordered directive with threads Clause.
+! Without clause in ordered direcitve, it behaves as if threads clause is
+! specified.
+
+! RUN: bbc -fopenmp -emit-fir %s -o - | FileCheck %s --check-prefix=FIRDialect
+! RUN: bbc -fopenmp -emit-fir %s -o - | \
+! RUN:   tco --disable-llvm --print-ir-after=fir-to-llvm-ir 2>&1 | \
+! RUN:   FileCheck %s --check-prefix=LLVMIRDialect
+! RUN: bbc -fopenmp -emit-fir %s -o - | tco | FileCheck %s --check-prefix=LLVMIR
+
+subroutine ordered
+        integer :: i
+        integer :: a(20)
+
+!FIRDialect: omp.ordered_region  {
+!LLVMIRDialect: omp.ordered_region  {
+!LLVMIR: [[TMP0:%.*]] = call i32 @__kmpc_global_thread_num(%struct.ident_t* @[[GLOB0:[0-9]+]]), !dbg !{{.*}}
+!LLVMIR-NEXT: call void @__kmpc_ordered(%struct.ident_t* @[[GLOB0]], i32 [[TMP0]]), !dbg !{{.*}}
+!$OMP ORDERED
+        a(i) = a(i-1) + 1
+!FIRDialect:   omp.terminator
+!FIRDialect-NEXT: }
+!LLVMIRDialect:   omp.terminator
+!LLVMIRDialect-NEXT: }
+!LLVMIR: call void @__kmpc_end_ordered(%struct.ident_t* @[[GLOB0]], i32 [[TMP0]]), !dbg !{{.*}}
+!$OMP END ORDERED
+
+!FIRDialect: omp.ordered_region  {
+!LLVMIRDialect: omp.ordered_region  {
+!LLVMIR: [[TMP1:%.*]] = call i32 @__kmpc_global_thread_num(%struct.ident_t* @[[GLOB1:[0-9]+]]), !dbg !{{.*}}
+!LLVMIR-NEXT: call void @__kmpc_ordered(%struct.ident_t* @[[GLOB1]], i32 [[TMP1]]), !dbg !{{.*}}
+!$OMP ORDERED THREADS
+        a(i) = a(i-1) + 1
+!FIRDialect:   omp.terminator
+!FIRDialect-NEXT: }
+!LLVMIRDialect:   omp.terminator
+!LLVMIRDialect-NEXT: }
+!LLVMIR: call void @__kmpc_end_ordered(%struct.ident_t* @[[GLOB1]], i32 [[TMP1]]), !dbg !{{.*}}
+!LLVMIR-NEXT: ret void, !dbg !{{.*}}
+!$OMP END ORDERED
+
+end