What Is the Options Greek That Measures Sensitivity to Volatility?

The options Greek that measures sensitivity to volatility is Vega. Vega quantifies the change in an option's premium for every 1% change in the underlying asset's implied volatility.

A high Vega indicates that the option's price is highly responsive to changes in market expectation of future price swings. Vega is highest for ATM options and for options with a longer time to expiration.