diff --git a/cpp/src/arrow/compute/kernels/vector_hash.cc b/cpp/src/arrow/compute/kernels/vector_hash.cc
index 90ec9e365c35..f42972e18af0 100644
--- a/cpp/src/arrow/compute/kernels/vector_hash.cc
+++ b/cpp/src/arrow/compute/kernels/vector_hash.cc
@@ -550,6 +550,7 @@ KernelInit GetHashInit(Type::type type_id) {
       return HashInit<RegularHashKernel<UInt8Type, Action>>;
     case Type::INT16:
     case Type::UINT16:
+    case Type::HALF_FLOAT:
       return HashInit<RegularHashKernel<UInt16Type, Action>>;
     case Type::INT32:
     case Type::UINT32:
@@ -700,6 +701,13 @@ void AddHashKernels(VectorFunction* func, VectorKernel base, OutputType out_ty)
     DCHECK_OK(func->AddKernel(base));
   }
 
+  // float16() is not part of PrimitiveTypes() (FloatingPointTypes() only covers
+  // float32 and float64; see GH-43017), so it must be registered explicitly. Like
+  // float32 and float64, it is hashed by its raw bit pattern (via UInt16Type).
+  base.init = GetHashInit<Action>(Type::HALF_FLOAT);
+  base.signature = KernelSignature::Make({float16()}, out_ty);
+  DCHECK_OK(func->AddKernel(base));
+
   // Parametric types that we want matching to be dependent only on type id
   auto parametric_types = {Type::TIME32, Type::TIME64, Type::TIMESTAMP, Type::DURATION,
                            Type::FIXED_SIZE_BINARY};
diff --git a/cpp/src/arrow/compute/kernels/vector_hash_test.cc b/cpp/src/arrow/compute/kernels/vector_hash_test.cc
index b0fa296e0074..5b066ab782f4 100644
--- a/cpp/src/arrow/compute/kernels/vector_hash_test.cc
+++ b/cpp/src/arrow/compute/kernels/vector_hash_test.cc
@@ -403,6 +403,44 @@ TEST_F(TestHashKernel, DictEncodeBoolean) {
       ArrayFromJSON(boolean(), "[true]"), ArrayFromJSON(int32(), "[0, null, 0]"));
 }
 
+// float16 is not part of PrimitiveTypes(), so it is not covered by
+// TestHashKernelPrimitive above and gets its own coverage here. Like float32 and
+// float64, it is hashed by its raw bit pattern.
+TEST_F(TestHashKernel, UniqueHalfFloat) {
+  CheckUnique(ArrayFromJSON(float16(), "[1.5, 2.5, null, 1.5, 3.5, null]"),
+              ArrayFromJSON(float16(), "[1.5, 2.5, null, 3.5]"));
+
+  // No nulls
+  CheckUnique(ArrayFromJSON(float16(), "[1.5, 2.5, 1.5, 3.5]"),
+              ArrayFromJSON(float16(), "[1.5, 2.5, 3.5]"));
+
+  // Sliced
+  CheckUnique(ArrayFromJSON(float16(), "[1.5, 2.5, null, 3.5, 2.5, 1.5]")->Slice(1, 4),
+              ArrayFromJSON(float16(), "[2.5, null, 3.5]"));
+}
+
+TEST_F(TestHashKernel, ValueCountsHalfFloat) {
+  CheckValueCounts(ArrayFromJSON(float16(), "[1.5, 2.5, null, 1.5, 3.5, null]"),
+                   ArrayFromJSON(float16(), "[1.5, 2.5, null, 3.5]"),
+                   ArrayFromJSON(int64(), "[2, 1, 2, 1]"));
+}
+
+TEST_F(TestHashKernel, DictEncodeHalfFloat) {
+  CheckDictEncode(ArrayFromJSON(float16(), "[1.5, 2.5, null, 1.5, 3.5, null]"),
+                  ArrayFromJSON(float16(), "[1.5, 2.5, 3.5]"),
+                  ArrayFromJSON(int32(), "[0, 1, null, 0, 2, null]"));
+
+  // No nulls
+  CheckDictEncode(ArrayFromJSON(float16(), "[1.5, 2.5, 1.5, 3.5]"),
+                  ArrayFromJSON(float16(), "[1.5, 2.5, 3.5]"),
+                  ArrayFromJSON(int32(), "[0, 1, 0, 2]"));
+
+  // Sliced
+  CheckDictEncode(
+      ArrayFromJSON(float16(), "[1.5, 2.5, null, 3.5, 2.5, 1.5]")->Slice(1, 4),
+      ArrayFromJSON(float16(), "[2.5, 3.5]"), ArrayFromJSON(int32(), "[0, null, 1, 0]"));
+}
+
 template <typename ArrowType>
 class TestHashKernelBinaryTypes : public TestHashKernel {
  protected: