This paper explores the meaning and use of inclusive curriculum design by operationally defining "inclusive curriculum" and delineating the characteristics of this curriculum design. A systematic review was conducted that incorporates both peer-reviewed and non-peer-reviewed sources so that scholar and practitioner perspectives of inclusive curricula are considered. From this review, the development of inclusive curricula over the past 50 years is uncovered, inclusive curriculum is defined, and related theories and curricular designs are discussed. The systematic review resulted in the emergence of three core principles and six defining characteristics of inclusive curricula. Across K-12 and higher education settings, an inclusive curriculum (a) addresses discrimination, (b) meets the needs of all students, and (b) encompasses content, pedagogy, and assessment methods. Additionally, an inclusive curriculum is welcoming, accessible, challenging, flexible, intentional, and authentic. These principles and characteristics provide a framework for inclusive curriculum that educators can use to design and implement inclusive curricula across a variety of educational settings, as well as evaluate existing curricula to make them more inclusive.