The objective of the present study is to develop a measurement tool to assess 21st Century learning and innovation skills of primary school students. Study data was collected from 632 fourth grade students in five different primary schools during 2014 - 2015 academic year and data obtained from 609 fourth grade students were utilized in the study. The scale was developed in six stages. These were; establishing the scale items, consultation of experts, pretest stage, determination of structural validity, reliability assessment, and finalization of the scale, respectively. Cronbach alpha reliability coefficient for the whole scale, which consisted of three factors, was calculated as 0.95. 0.89. As a result of the current study, a Likert-type 21st Century learning and innovation skills scale with 39 items was developed. 20 items of the scale were related to creativity and innovation skills, 12 were related to critical thinking and problem solving skills, and 7 were related to cooperation and communication skills.