diff --git a/packages/react-native/ReactCommon/react/renderer/components/view/CSSTokenizer.cpp b/packages/react-native/ReactCommon/react/renderer/components/view/CSSTokenizer.cpp
new file mode 100644
index 00000000000..945d395e442
--- /dev/null
+++ b/packages/react-native/ReactCommon/react/renderer/components/view/CSSTokenizer.cpp
@@ -0,0 +1,187 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <cmath>
+#include <cstdint>
+
+#include <react/debug/react_native_assert.h>
+#include <react/renderer/components/view/CSSTokenizer.h>
+
+namespace facebook::react {
+
+CSSTokenizer::CSSTokenizer(std::string_view characters)
+    : remainingCharacters_{characters} {}
+
+CSSToken CSSTokenizer::next() {
+  // https://www.w3.org/TR/css-syntax-3/#token-diagrams
+  char nextChar = peek();
+  if (isWhitespace(nextChar)) {
+    return consumeWhitespace();
+  } else if (nextChar == '+') {
+    if (isDigit(peekNext())) {
+      return consumeNumeric();
+    } else {
+      return consumeDelim();
+    }
+  } else if (nextChar == '-') {
+    if (isDigit(peekNext())) {
+      return consumeNumeric();
+    } else {
+      return consumeDelim();
+    }
+  } else if (isDigit(nextChar)) {
+    return consumeNumeric();
+  } else if (isIdentStart(nextChar)) {
+    return consumeIdent();
+  } else if (nextChar == '\0') {
+    return CSSToken{CSSTokenType::EndOfFile};
+  } else {
+    return consumeDelim();
+  }
+}
+
+char CSSTokenizer::peek() const {
+  auto index = position_;
+  return index >= remainingCharacters_.size() ? '\0'
+                                              : remainingCharacters_[index];
+}
+
+char CSSTokenizer::peekNext() const {
+  auto index = position_ + 1;
+  return index >= remainingCharacters_.size() ? '\0'
+                                              : remainingCharacters_[index];
+}
+
+void CSSTokenizer::advance() {
+  react_native_assert(remainingCharacters_.size() > position_);
+  position_ += 1;
+}
+
+CSSToken CSSTokenizer::consumeDelim() {
+  advance();
+  return {CSSTokenType::Delim, consumeRunningValue()};
+}
+
+CSSToken CSSTokenizer::consumeWhitespace() {
+  while (isWhitespace(peek())) {
+    advance();
+  }
+
+  consumeRunningValue();
+  return CSSToken{CSSTokenType::WhiteSpace};
+}
+
+CSSToken CSSTokenizer::consumeNumber() {
+  // https://www.w3.org/TR/css-syntax-3/#consume-number
+  // https://www.w3.org/TR/css-syntax-3/#convert-a-string-to-a-number
+  int32_t signPart = 1.0;
+  if (peek() == '+' || peek() == '-') {
+    if (peek() == '-') {
+      signPart = -1.0;
+    }
+    advance();
+  }
+
+  int32_t intPart = 0;
+  while (isDigit(peek())) {
+    intPart = intPart * 10 + (peek() - '0');
+    advance();
+  }
+
+  int32_t fractionalPart = 0;
+  int32_t fractionDigits = 0;
+  if (peek() == '.') {
+    advance();
+    while (isDigit(peek())) {
+      fractionalPart = fractionalPart * 10 + (peek() - '0');
+      fractionDigits++;
+      advance();
+    }
+  }
+
+  int32_t exponentSign = 1.0;
+  int32_t exponentPart = 0;
+  if (peek() == 'e' || peek() == 'E') {
+    advance();
+    if (peek() == '+' || peek() == '-') {
+      if (peek() == '-') {
+        exponentSign = -1.0;
+      }
+      advance();
+    }
+
+    while (isDigit(peek())) {
+      exponentPart = exponentPart * 10 + (peek() - '0');
+      advance();
+    }
+  }
+
+  auto value = static_cast<float>(
+      signPart * (intPart + (fractionalPart * std::pow(10, -fractionDigits))) *
+      std::pow(10, exponentSign * exponentPart));
+
+  consumeRunningValue();
+  return {CSSTokenType::Number, value};
+}
+
+CSSToken CSSTokenizer::consumeNumeric() {
+  // https://www.w3.org/TR/css-syntax-3/#consume-numeric-token
+  auto numberToken = consumeNumber();
+
+  if (isIdent(peek())) {
+    auto ident = consumeIdent();
+    return {
+        CSSTokenType::Dimension,
+        numberToken.numericValue(),
+        ident.stringValue()};
+  } else if (peek() == '%') {
+    advance();
+    consumeRunningValue();
+    return {CSSTokenType::Percent, numberToken.numericValue()};
+  } else {
+    return numberToken;
+  }
+}
+
+CSSToken CSSTokenizer::consumeIdent() {
+  // https://www.w3.org/TR/css-syntax-3/#consume-an-ident-sequence
+  while (isIdent(peek())) {
+    advance();
+  }
+
+  return {CSSTokenType::Ident, consumeRunningValue()};
+}
+
+std::string_view CSSTokenizer::consumeRunningValue() {
+  auto next = remainingCharacters_.substr(0, position_);
+  remainingCharacters_ = remainingCharacters_.substr(next.size());
+  position_ = 0;
+  return next;
+}
+
+/*static*/ bool CSSTokenizer::isDigit(char c) {
+  // https://www.w3.org/TR/css-syntax-3/#digit
+  return c >= '0' && c <= '9';
+}
+
+/*static*/ bool CSSTokenizer::isIdentStart(char c) {
+  // https://www.w3.org/TR/css-syntax-3/#ident-start-code-point
+  return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z') || c == '_' ||
+      static_cast<unsigned char>(c) > 0x80;
+}
+
+/*static*/ bool CSSTokenizer::isIdent(char c) {
+  // https://www.w3.org/TR/css-syntax-3/#ident-code-point
+  return isIdentStart(c) || isDigit(c) || c == '-';
+}
+
+/*static*/ bool CSSTokenizer::isWhitespace(char c) {
+  // https://www.w3.org/TR/css-syntax-3/#whitespace
+  return c == ' ' || c == '\t' || c == '\r' || c == '\n';
+}
+
+} // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/renderer/components/view/CSSTokenizer.h b/packages/react-native/ReactCommon/react/renderer/components/view/CSSTokenizer.h
new file mode 100644
index 00000000000..647e9bd8789
--- /dev/null
+++ b/packages/react-native/ReactCommon/react/renderer/components/view/CSSTokenizer.h
@@ -0,0 +1,101 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#pragma once
+
+#include <string_view>
+
+namespace facebook::react {
+
+/**
+ * One of the tokens defined as part of
+ * https://www.w3.org/TR/css-syntax-3/#tokenizer-definitions
+ */
+enum class CSSTokenType {
+  Delim,
+  Dimension,
+  EndOfFile,
+  Ident,
+  Number,
+  Percent,
+  WhiteSpace,
+};
+
+struct CSSToken {
+  explicit CSSToken(CSSTokenType type) : type_(type) {}
+  CSSToken(CSSTokenType type, std::string_view value)
+      : type_{type}, stringValue_{value} {}
+  CSSToken(CSSTokenType type, float value)
+      : type_{type}, numericValue_{value} {}
+  CSSToken(CSSTokenType type, float value, std::string_view unit)
+      : type_{type}, numericValue_{value}, unit_{unit} {}
+
+  CSSToken(const CSSToken& other) = default;
+  CSSToken(CSSToken&& other) = default;
+  CSSToken& operator=(const CSSToken& other) = default;
+  CSSToken& operator=(CSSToken&& other) = default;
+
+  CSSTokenType type() const {
+    return type_;
+  }
+
+  std::string_view stringValue() const {
+    return stringValue_;
+  }
+
+  float numericValue() const {
+    return numericValue_;
+  }
+
+  std::string_view unit() const {
+    return unit_;
+  }
+
+  bool operator==(const CSSToken& other) const = default;
+
+ private:
+  CSSTokenType type_;
+  std::string_view stringValue_;
+  float numericValue_{0.0f};
+  std::string_view unit_;
+};
+
+/**
+ * A minimal tokenizer for a subset of CSS syntax.
+ * `auto`).
+ *
+ * This is based on the W3C CSS Syntax specification, with simplifications made
+ * for syntax which React Native does not attempt to support.
+ * https://www.w3.org/TR/css-syntax-3/#tokenizing-and-parsing
+ */
+class CSSTokenizer {
+ public:
+  explicit CSSTokenizer(std::string_view characters);
+  CSSToken next();
+
+ private:
+  char peek() const;
+  char peekNext() const;
+  void advance();
+
+  CSSToken consumeDelim();
+  CSSToken consumeWhitespace();
+  CSSToken consumeNumber();
+  CSSToken consumeNumeric();
+  CSSToken consumeIdent();
+
+  std::string_view consumeRunningValue();
+
+  static bool isDigit(char c);
+  static bool isIdentStart(char c);
+  static bool isIdent(char c);
+  static bool isWhitespace(char c);
+
+  std::string_view remainingCharacters_;
+  size_t position_{0};
+};
+} // namespace facebook::react
diff --git a/packages/react-native/ReactCommon/react/renderer/components/view/tests/CSSTokenizerTest.cpp b/packages/react-native/ReactCommon/react/renderer/components/view/tests/CSSTokenizerTest.cpp
new file mode 100644
index 00000000000..9a11a79b62c
--- /dev/null
+++ b/packages/react-native/ReactCommon/react/renderer/components/view/tests/CSSTokenizerTest.cpp
@@ -0,0 +1,144 @@
+/*
+ * Copyright (c) Meta Platforms, Inc. and affiliates.
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+#include <gtest/gtest.h>
+#include <react/renderer/components/view/CSSTokenizer.h>
+#include <deque>
+
+namespace facebook::react {
+
+static void expectTokens(
+    std::string_view characters,
+    std::initializer_list<CSSToken> expectedTokens) {
+  CSSTokenizer tokenizer{characters};
+
+  for (const auto& expectedToken : expectedTokens) {
+    auto nextToken = tokenizer.next();
+    EXPECT_EQ(nextToken.type(), expectedToken.type());
+    EXPECT_EQ(nextToken.stringValue(), expectedToken.stringValue());
+    EXPECT_EQ(nextToken.numericValue(), expectedToken.numericValue());
+    EXPECT_EQ(nextToken.unit(), expectedToken.unit());
+    EXPECT_EQ(nextToken, expectedToken);
+  }
+}
+
+TEST(CSSTokenizer, eof_values) {
+  expectTokens("", {CSSToken{CSSTokenType::EndOfFile}});
+}
+
+TEST(CSSTokenizer, whitespace_values) {
+  expectTokens(
+      " ",
+      {CSSToken{CSSTokenType::WhiteSpace}, CSSToken{CSSTokenType::EndOfFile}});
+  expectTokens(
+      " \t",
+      {CSSToken{CSSTokenType::WhiteSpace}, CSSToken{CSSTokenType::EndOfFile}});
+  expectTokens(
+      "\n   \t",
+      {CSSToken{CSSTokenType::WhiteSpace}, CSSToken{CSSTokenType::EndOfFile}});
+}
+
+TEST(CSSTokenizer, ident_values) {
+  expectTokens(
+      "auto",
+      {CSSToken{CSSTokenType::Ident, "auto"},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "inset auto left",
+      {CSSToken{CSSTokenType::Ident, "inset"},
+       CSSToken{CSSTokenType::WhiteSpace},
+       CSSToken{CSSTokenType::Ident, "auto"},
+       CSSToken{CSSTokenType::WhiteSpace},
+       CSSToken{CSSTokenType::Ident, "left"},
+       CSSToken{CSSTokenType::EndOfFile}});
+}
+
+TEST(CSSTokenizer, number_values) {
+  expectTokens(
+      "12",
+      {CSSToken{CSSTokenType::Number, 12.0f},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "-5",
+      {CSSToken{CSSTokenType::Number, -5.0f},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "123.0",
+      {CSSToken{CSSTokenType::Number, 123.0f},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "4.2E-1",
+      {CSSToken{CSSTokenType::Number, 4.2e-1},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "6e-10",
+      {CSSToken{CSSTokenType::Number, 6e-10f},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "+81.07e+0",
+      {CSSToken{CSSTokenType::Number, +81.07e+0},
+       CSSToken{CSSTokenType::EndOfFile}});
+}
+
+TEST(CSSTokenizer, dimension_values) {
+  expectTokens(
+      "12px",
+      {CSSToken{CSSTokenType::Dimension, 12.0f, "px"},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "463.2abc",
+      {CSSToken{CSSTokenType::Dimension, 463.2, "abc"},
+       CSSToken{CSSTokenType::EndOfFile}});
+}
+
+TEST(CSSTokenizer, percent_values) {
+  expectTokens(
+      "12%",
+      {CSSToken{CSSTokenType::Percent, 12.0f},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "-28.5%",
+      {CSSToken{CSSTokenType::Percent, -28.5f},
+       CSSToken{CSSTokenType::EndOfFile}});
+}
+
+TEST(CSSTokenizer, mixed_values) {
+  expectTokens(
+      "12px   -100vh",
+      {CSSToken{CSSTokenType::Dimension, 12.0f, "px"},
+       CSSToken{CSSTokenType::WhiteSpace},
+       CSSToken{CSSTokenType::Dimension, -100.0f, "vh"},
+       CSSToken{CSSTokenType::EndOfFile}});
+}
+
+TEST(CSSTokenizer, invalid_values) {
+  expectTokens(
+      "100*",
+      {CSSToken{CSSTokenType::Number, 100.0f},
+       CSSToken{CSSTokenType::Delim, "*"},
+       CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "+",
+      {CSSToken{CSSTokenType::Delim, "+"}, CSSToken{CSSTokenType::EndOfFile}});
+
+  expectTokens(
+      "(%",
+      {CSSToken{CSSTokenType::Delim, "("},
+       CSSToken{CSSTokenType::Delim, "%"},
+       CSSToken{CSSTokenType::EndOfFile}});
+}
+
+} // namespace facebook::react