diff --git a/cpp/src/arrow/util/decimal.cc b/cpp/src/arrow/util/decimal.cc
index c8457eae8..aa2b41cc9 100644
--- a/cpp/src/arrow/util/decimal.cc
+++ b/cpp/src/arrow/util/decimal.cc
@@ -111,7 +111,11 @@ struct DecimalRealConversion : public BaseDecimalRealConversion {
 
     // 2. Losslessly convert `real` to `mant * 2**k`
     int binary_exp = 0;
+#ifdef __EMSCRIPTEN__
+    const Real real_mant = std::frexpf(real, &binary_exp);
+#else
     const Real real_mant = std::frexp(real, &binary_exp);
+#endif
     // `real_mant` is within 0.5 and 1 and has M bits of precision.
     // Multiply it by 2^M to get an exact integer.
     const uint64_t mant = static_cast<uint64_t>(std::ldexp(real_mant, kMantissaBits));
diff --git a/cpp/src/arrow/util/value_parsing.h b/cpp/src/arrow/util/value_parsing.h
index 609906052..1e3dfae7c 100644
--- a/cpp/src/arrow/util/value_parsing.h
+++ b/cpp/src/arrow/util/value_parsing.h
@@ -804,7 +804,7 @@ static inline bool ParseTimestampStrptime(const char* buf, size_t length,
   std::string clean_copy(buf, length);
   struct tm result;
   memset(&result, 0, sizeof(struct tm));
-#ifdef _WIN32
+#if defined(_WIN32) || defined(__EMSCRIPTEN__)
   char* ret = arrow_strptime(clean_copy.c_str(), format, &result);
 #else
   char* ret = strptime(clean_copy.c_str(), format, &result);
diff --git a/cpp/src/arrow/vendored/xxhash/xxhash.h b/cpp/src/arrow/vendored/xxhash/xxhash.h
index a18e8c762..235590b19 100644
--- a/cpp/src/arrow/vendored/xxhash/xxhash.h
+++ b/cpp/src/arrow/vendored/xxhash/xxhash.h
@@ -169,6 +169,11 @@
  * xxHash prototypes and implementation
  */
 
+
+#ifdef __EMSCRIPTEN__
+#include <emscripten.h>
+#endif
+
 #if defined (__cplusplus)
 extern "C" {
 #endif
@@ -3422,6 +3427,7 @@ XXH_PUBLIC_API XXH64_hash_t XXH64_hashFromCanonical(XXH_NOESCAPE const XXH64_can
 #  endif
 #endif
 
+
 #if defined(__GNUC__) || defined(__clang__)
 #  if defined(__ARM_FEATURE_SVE)
 #    include <arm_sve.h>