diff --git a/docs/design/coreclr/botr/readytorun-format.md b/docs/design/coreclr/botr/readytorun-format.md
index b48e55339d9ec6..0a2ebf34cc72b3 100644
--- a/docs/design/coreclr/botr/readytorun-format.md
+++ b/docs/design/coreclr/botr/readytorun-format.md
@@ -1059,6 +1059,7 @@ The string format is:
 | `l` | returns `i64` |
 | `f` | returns `f32` |
 | `d` | returns `f64` |
+| `V` | returns `v128` (a `Vector128<T>`, or a 16-byte `Vector<T>`) |
 | `S<N>` | struct return via hidden buffer, `N` is the struct size in bytes |
 
 **This pointer** (if the method has a `this` parameter):
@@ -1085,6 +1086,7 @@ it knows a hidden retbuf pointer argument is present in the Wasm parameter list.
 | `l` | `i64` parameter |
 | `f` | `f32` parameter |
 | `d` | `f64` parameter |
+| `V` | `v128` parameter (a `Vector128<T>`, or a 16-byte `Vector<T>`, passed by value) |
 | `S<N>` | struct parameter passed by reference, `<N>` is the struct size in bytes |
 | `e` | empty struct parameter — elided from Wasm args but present in the string |
 
diff --git a/src/coreclr/vm/wasm/helpers.cpp b/src/coreclr/vm/wasm/helpers.cpp
index 5295261aa3b27d..2f6ff7fddb2f73 100644
--- a/src/coreclr/vm/wasm/helpers.cpp
+++ b/src/coreclr/vm/wasm/helpers.cpp
@@ -989,6 +989,7 @@ namespace
         ToI64,
         ToF32,
         ToF64,
+        ToV128,
         ToStruct,   // S<N> — multi-field struct passed by pointer, structSize holds the size
         ToEmpty,    // e — empty struct, takes no wasm argument
     };
@@ -1032,6 +1033,23 @@ namespace
         }
 
         MethodTable* pMT = th.AsMethodTable();
+
+        bool isSupportedVectorBaseType =
+            pMT->IsIntrinsicType() &&
+            (pMT->GetNumGenericArgs() == 1) &&
+            CorIsNumericalType(pMT->GetInstantiation()[0].GetSignatureCorElementType());
+        if (isSupportedVectorBaseType)
+        {
+            PTR_MethodTable pVector128MT = CoreLibBinder::GetClassIfExist(CLASS__VECTOR128T);
+            PTR_MethodTable pVectorTMT = CoreLibBinder::GetClassIfExist(CLASS__VECTORT);
+
+            if ((pVector128MT != nullptr && pMT->HasSameTypeDefAs(pVector128MT)) ||
+                ((size == 16) && (pVectorTMT != nullptr) && pMT->HasSameTypeDefAs(pVectorTMT)))
+            {
+                return { ConvertType::ToV128, 0 };
+            }
+        }
+
         uint32_t numInstanceFields = pMT->GetNumInstanceFields();
 
         // WASM-TODO: Empty structs should return ToEmpty once .NET
@@ -1107,6 +1125,7 @@ namespace
             case ConvertType::ToI64:       c = 'l'; break;
             case ConvertType::ToF32:       c = 'f'; break;
             case ConvertType::ToF64:       c = 'd'; break;
+            case ConvertType::ToV128:      c = 'V'; break;
             case ConvertType::ToEmpty:     c = 'e'; break;
             case ConvertType::ToStruct:
             {