This article highlights the scholarly contribution of the Iranian-born Muslim scholar-activist Ziba Mir-Hosseini to the academic field of gender and Islam. In the first part, Mir-Hosseini's thought is positioned within the larger processes of the shifting loci of authority and normativity in contemporary Islamic discourses, particularly with reference to the emergence of what will here be termed critical-progressive Muslim scholar-activists. There follows a brief justification as to why a study of Mir-Hosseini's thought in relation to gender and Islam warrants examination. Mir-Hosseini's personal journey in the field of gender and Islam is then outlined and her major contributions to the field are noted. This is followed by a discussion of the support Mir-Hosseini finds for her ideas in the hermeneutical theories employed by reformist male Muslim scholars, and then an examination of her views on the relationship between Islamic feminism discourses and (neo-)traditional expressions of Islam. Mir-Hosseini's deconstruction of the assumptions governing classical Muslim family law and ethics that have been re-appropriated and legally enforced by some contemporary Muslim majority nation states is presented next, followed by a discussion of her proposals for the reform of Muslim family law and ethics. The final section discusses Mir Hosseini's activism with special reference to her involvement with Musawah, the global movement for equality in Muslim family law based in Kuala Lumpur, Malaysia.