diff --git a/cpp/src/arrow/python/deserialize.cc b/cpp/src/arrow/python/deserialize.cc
index f13070a5883..979399646ad 100644
--- a/cpp/src/arrow/python/deserialize.cc
+++ b/cpp/src/arrow/python/deserialize.cc
@@ -21,6 +21,7 @@
 
 #include <cstdint>
 #include <memory>
+#include <sstream>
 #include <string>
 #include <utility>
 #include <vector>
@@ -195,8 +196,10 @@ std::vector<int8_t> GetPythonTypes(const UnionArray& data) {
   std::vector<int8_t> result;
   auto type = data.type();
   for (int i = 0; i < type->num_children(); ++i) {
-    // stoi is locale dependent, but should be ok for small integers
-    result.push_back(static_cast<int8_t>(std::stoi(type->child(i)->name())));
+    std::istringstream convert(type->child(i)->name());
+    int tag;
+    convert >> tag;
+    result.push_back(static_cast<int8_t>(tag));
   }
   return result;
 }
diff --git a/cpp/src/arrow/python/serialize.cc b/cpp/src/arrow/python/serialize.cc
index 3ccdfc8eee5..4d5b02984cf 100644
--- a/cpp/src/arrow/python/serialize.cc
+++ b/cpp/src/arrow/python/serialize.cc
@@ -90,8 +90,9 @@ class SequenceBuilder {
                          MakeBuilderFn make_builder) {
     if (!*child_builder) {
       child_builder->reset(make_builder());
-      // std::to_string is locale dependent, but should be ok for small integers
-      type_map_[tag] = builder_->AppendChild(*child_builder, std::to_string(tag));
+      std::ostringstream convert;
+      convert << static_cast<int>(tag);
+      type_map_[tag] = builder_->AppendChild(*child_builder, convert.str());
     }
     return Update(child_builder->get(), type_map_[tag]);
   }