Numeracy has emerged as a driver for curriculum reform in many international contexts. This paper compares curriculum reform processes in two countries, Australia and Ireland, which have introduced policies for embedding numeracy across the school curriculum. Our analysis examines the rationale for including numeracy in the curriculum, how numeracy is represented in the curriculum, and who is deemed to be responsible for developing students’ numeracy. The findings highlight the need for “joined up” policy instruments addressing curriculum, assessment, and teacher preparation, as well as the relationship of numeracy to mathematics.