diff --git a/kleidicv/include/kleidicv/neon.h b/kleidicv/include/kleidicv/neon.h
index 9fc3974ec583eae92ec7b63425d1b9251f3874ac..ecafd7d388ed1cc6adcc3d23a07f9dfab55c8ef5 100644
--- a/kleidicv/include/kleidicv/neon.h
+++ b/kleidicv/include/kleidicv/neon.h
@@ -170,6 +170,9 @@ class VecTraitsBase : public VectorTypes<ScalarType> {
     return kVectorLength / sizeof(ScalarType);
   }
 
+  // Maximum number of lanes in a vector.
+  static constexpr size_t max_num_lanes() { return num_lanes(); }
+
   // Loads a single vector from 'src'.
   static inline void load(const ScalarType *src, VectorType &vec) {
     vec = vld1q(&src[0]);
diff --git a/kleidicv/include/kleidicv/sve2.h b/kleidicv/include/kleidicv/sve2.h
index 43e2e40d561a08b0bc172d0d4c5ab3c0788d427b..ebbc5d04e673d17d634c6759b9a4423aa0070805 100644
--- a/kleidicv/include/kleidicv/sve2.h
+++ b/kleidicv/include/kleidicv/sve2.h
@@ -146,6 +146,11 @@ class VecTraitsBase : public VectorTypes<ScalarType> {
     return static_cast<size_t>(svcnt());
   }
 
+  // Maximum number of lanes in a vector.
+  static constexpr size_t max_num_lanes() KLEIDICV_STREAMING_COMPATIBLE {
+    return 256 / sizeof(ScalarType);
+  }
+
   // Loads a single vector from 'src'.
   static inline void load(Context ctx, const ScalarType *src,
                           VectorType &vec) KLEIDICV_STREAMING_COMPATIBLE {
diff --git a/kleidicv/src/arithmetics/sum_api.cpp b/kleidicv/src/arithmetics/sum_api.cpp
index 2846cbc83419dbd09df8c357c1cae3e331ea05cc..2959587e80acf002a41c5427a4aa4f23f1e36683 100644
--- a/kleidicv/src/arithmetics/sum_api.cpp
+++ b/kleidicv/src/arithmetics/sum_api.cpp
@@ -15,7 +15,24 @@ kleidicv_error_t sum(const T *src, size_t src_stride, size_t width,
 
 }  // namespace neon
 
+namespace sve2 {
+
+template <typename T>
+kleidicv_error_t sum(const T *src, size_t src_stride, size_t width,
+                     size_t height, T *sum);
+
+}  // namespace sve2
+
+namespace sme2 {
+
+template <typename T>
+kleidicv_error_t sum(const T *src, size_t src_stride, size_t width,
+                     size_t height, T *sum);
+
+}  // namespace sme2
+
 }  // namespace kleidicv
 
 KLEIDICV_MULTIVERSION_C_API(kleidicv_sum_f32, &kleidicv::neon::sum<float>,
-                            nullptr, nullptr);
+                            KLEIDICV_SVE2_IMPL_IF(&kleidicv::sve2::sum<float>),
+                            KLEIDICV_SME2_IMPL_IF(&kleidicv::sme2::sum<float>));
diff --git a/kleidicv/src/arithmetics/sum_sc.h b/kleidicv/src/arithmetics/sum_sc.h
new file mode 100644
index 0000000000000000000000000000000000000000..8109665cb2a7f1a69a19ec1e900f20b086b8d2c5
--- /dev/null
+++ b/kleidicv/src/arithmetics/sum_sc.h
@@ -0,0 +1,72 @@
+// SPDX-FileCopyrightText: 2024 Arm Limited and/or its affiliates <open-source-office@arm.com>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+#ifndef KLEIDICV_SUM_SC_H
+#define KLEIDICV_SUM_SC_H
+
+#include "kleidicv/kleidicv.h"
+#include "kleidicv/sve2.h"
+#include "kleidicv/utils.h"
+
+namespace KLEIDICV_TARGET_NAMESPACE {
+
+template <typename ScalarType>
+class Sum final : public UnrollTwice {
+ public:
+  using ContextType = Context;
+  using VecTraits = KLEIDICV_TARGET_NAMESPACE::VecTraits<ScalarType>;
+  using VectorType = typename VecTraits::VectorType;
+
+  explicit Sum(VectorType &accumulator) KLEIDICV_STREAMING_COMPATIBLE
+      : accumulator_{accumulator} {
+    accumulator_ = VecTraits::svdup(0);
+  }
+
+  void vector_path(ContextType ctx,
+                   VectorType src) KLEIDICV_STREAMING_COMPATIBLE {
+    accumulator_ = svadd_m(ctx.predicate(), accumulator_, src);
+  }
+
+  ScalarType get_sum() KLEIDICV_STREAMING_COMPATIBLE {
+    ScalarType accumulator_final[VecTraits::max_num_lanes()] = {0};
+    svst1(VecTraits::svptrue(), accumulator_final, accumulator_);
+
+    ScalarType sum = 0;
+    for (size_t i = 0; i != VecTraits::num_lanes(); ++i) {
+      sum += accumulator_final[i];
+    }
+    return sum;
+  }
+
+ private:
+  VectorType &accumulator_;
+};
+
+template <typename ScalarType>
+kleidicv_error_t sum_sc(const ScalarType *src, size_t src_stride, size_t width,
+                        size_t height,
+                        ScalarType *sum) KLEIDICV_STREAMING_COMPATIBLE {
+  using VecTraits = KLEIDICV_TARGET_NAMESPACE::VecTraits<ScalarType>;
+  using VectorType = typename VecTraits::VectorType;
+
+  CHECK_POINTERS(sum);
+  CHECK_POINTER_AND_STRIDE(src, src_stride, height);
+  CHECK_IMAGE_SIZE(width, height);
+
+  Rectangle rect{width, height};
+  Rows<const ScalarType> src_rows{src, src_stride};
+
+  VectorType accumulator;
+  Sum<ScalarType> operation{accumulator};
+
+  apply_operation_by_rows(operation, rect, src_rows);
+
+  *sum = operation.get_sum();
+
+  return KLEIDICV_OK;
+}
+
+}  // namespace KLEIDICV_TARGET_NAMESPACE
+
+#endif  // KLEIDICV_SUM_SC_H
diff --git a/kleidicv/src/arithmetics/sum_sme2.cpp b/kleidicv/src/arithmetics/sum_sme2.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..51904798659043e1c44de55b478ff5c4f1f44030
--- /dev/null
+++ b/kleidicv/src/arithmetics/sum_sme2.cpp
@@ -0,0 +1,22 @@
+// SPDX-FileCopyrightText: 2024 Arm Limited and/or its affiliates <open-source-office@arm.com>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+#include "sum_sc.h"
+
+namespace kleidicv::sme2 {
+
+template <typename T>
+KLEIDICV_LOCALLY_STREAMING KLEIDICV_TARGET_FN_ATTRS kleidicv_error_t
+sum(const T *src, size_t src_stride, size_t width, size_t height, T *sum) {
+  return sum_sc(src, src_stride, width, height, sum);
+}
+
+#define KLEIDICV_INSTANTIATE_TEMPLATE(type)                            \
+  template KLEIDICV_TARGET_FN_ATTRS kleidicv_error_t sum<type>(        \
+      const type *src, size_t src_stride, size_t width, size_t height, \
+      type *sum)
+
+KLEIDICV_INSTANTIATE_TEMPLATE(float);
+
+}  // namespace kleidicv::sme2
diff --git a/kleidicv/src/arithmetics/sum_sve2.cpp b/kleidicv/src/arithmetics/sum_sve2.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..a1a0a5cf5626dcf1c94cd452a5120e0a9f34f20b
--- /dev/null
+++ b/kleidicv/src/arithmetics/sum_sve2.cpp
@@ -0,0 +1,23 @@
+// SPDX-FileCopyrightText: 2024 Arm Limited and/or its affiliates <open-source-office@arm.com>
+//
+// SPDX-License-Identifier: Apache-2.0
+
+#include "sum_sc.h"
+
+namespace kleidicv::sve2 {
+
+template <typename T>
+KLEIDICV_TARGET_FN_ATTRS kleidicv_error_t sum(const T *src, size_t src_stride,
+                                              size_t width, size_t height,
+                                              T *sum) {
+  return sum_sc(src, src_stride, width, height, sum);
+}
+
+#define KLEIDICV_INSTANTIATE_TEMPLATE(type)                            \
+  template KLEIDICV_TARGET_FN_ATTRS kleidicv_error_t sum<type>(        \
+      const type *src, size_t src_stride, size_t width, size_t height, \
+      type *sum)
+
+KLEIDICV_INSTANTIATE_TEMPLATE(float);
+
+}  // namespace kleidicv::sve2