This article examines the influence of Islamist movements on criminal legislation in Pakistan, with particular emphasis on the political dimensions of criminal law. The central question is how Islamism has shaped the Islamization of criminal law and reconfigured the relationship between the state, Sharia, and society. Adopting a historical-analytical approach and a case study methodology, the study traces the evolution of Pakistan’s criminal justice system from the country’s establishment in 1947 through the Islamization program of General Muhammad Zia-ul-Haq (1977–1988) to later reforms, particularly the Women’s Protection Act of 2006. The analysis shows that Islamization was not merely an effort to apply Islamic jurisprudence. Facing a legitimacy deficit, Zia presented the implementation of Sharia as both a religious obligation and a source of political legitimacy, introducing the Hudood Ordinances of 1979, the Qisas and Diyat laws, and institutions such as the Federal Shariat Court. Although Islamist actors, notably Jamaat-e-Islami, promoted these measures, the state adopted and applied Islamic norms selectively according to political considerations. Islamization therefore emerged as a negotiated and contested project shaped by the balance of power among state institutions, religious movements, legal elites, and social actors. Criticism from civil society, women’s rights activists, legal professionals, and international human rights bodies, particularly regarding women and religious minorities, prompted later revisions, most notably the 2006 Act, showing that Islamization was neither static nor irreversible. The study concludes that criminal law in Pakistan has become a key arena for redefining the relationship between Sharia, state authority, and political legitimacy.