"This Is Who I Am" debuted at number 1 on the ARIA Charts for the week beginning 18 October 2009. This is Amorosi's first number 1 single. The single held the top spot for a second week in a row – becoming the first Australian artist to debut at No. 1 and hold No. 1 single since Silverchair's "Straight Lines" in 2007. "This Is Who I Am" has achieved 2× platinum sales in Australia making it her most successful single to date in her homeland.