This chapter examines the context for the implementation of the global commitment to early childhood education (ECE) within the framing of the sustainable development goals (SDGs) under SDG 4.2. We first define the concept of ECE as broadly understood in the field of education and in practice related to a focus on education of children. The essay adopts chronological age of children served outside of the formal school system, which has traditionally been recognized as basic education, to represent the population captured under ECE in both pre-school and pre-primary settings. UNICEF identifies those ages 3-6 to fall into this category. We present an exploration of the challenges and opportunities presented by multiplicity in multilateral agencies and other agencies driving the international initiatives around advancing ECE and the means by which they promote education opportunities for children. We offer a comparative perspective on the delivery, types, and funding mechanisms of ECE services in both developing and developed country contexts, which informs the possibilities for the realization of the SDG goal of inclusive quality education for all. An examination of the socio-cultural and economic context of accessibility to inclusive and equitable quality ECE is also presented. An overview of settings within which ECE is provided is interrogated within differing national contexts. We conclude with challenges and opportunities for sustained accountability, monitoring and evaluation of SDG 4.2 interventions from a comparative perspective. [For the complete volume, "Annual Review of Comparative and International Education 2019. International Perspectives on Education and Society. Volume 39," see ED674880.]