The aim of the study is to obtain empirical evidence of transformational leadership abilities in improving OCB (organizational citizenship behavior), either directly or through mediation of organizational commitment. Partial Least Square quantitative approach was used to analyze data from 52 employees of four village offices in Purworejo District of Pasuruan City, namely Wirogunan, Tembokrejo, Sekargadung, and Purworejo Villages, which were taken as the research subject by means of census. The research obtained empirical findings that transformational leadership is able to increase organizational commitment and OCB. However, organizational commitment is not able to act as a strong mediator for the influence of transformational leadership on OCB employees of the Wirogunan, Tembokrejo, Sekargadung, and Purworejo Village Offices in Purworejo District, Pasuruan. This result is supported by respondents' responses to the variables of transformational leadership, organizational commitment, and OCB, all of which had high average scores. Tujuan penelitian adalah untuk mendapatkan bukti empiris kemampuan transformational leadership dalam meningkatkan OCB (organizational citizenship behavior), baik secara langsung maupun melalui mediasi komitmen organisasi. Pendekatan kuantitatif Partial Least Square digunakan untuk menganalisis data 52 pegawai empat kelurahan di Kecamatan Purworejo Kota Pasuruan, yakni: Kelurahan Wirogunan, Tembokrejo, Sekargadung, dan Purworejo, yang diambil secara sensus. Temuan empiris yang diperoleh bahwa transformational leadership mampu meningkatkan komitmen organisasi maupun OCB. Tetapi, komitmen organisasi tidak mampu berperan sebagai mediasi yang kuat atas pengaruh transformational leadership terhadap OCB pegawai Kelurahan Wirogunan, Tembokrejo, Sekargadung, dan Purworejo di Kecamatan Purworejo Kota Pasuruan. Hasil ini didukung oleh tanggapan responden atas variabel transformational leadership, komitmen organisasi, dan OCB yang memiliki nilai rata-rata tinggi.