This article describes the development and validation of the Information Literacy Reflection Tool (ILRT), a metacognitive self-assessment for use with undergraduate researchers. It was developed as a teaching and learning tool with the intent to help students recognize and engage the metacognitive domain as a step toward developing personal agency and self-regulation as lifelong, metaliterate learners. Throughout the scale development, three studies were conducted with nine expert reviewers and 44 community college students to consider content and face validity and 542 community college students as part of an item-reduction and construct validation effort. The resulting scale is most appropriately construed through a bifactor model and is made up of 57 items comprising a strong information literacy general factor and six specific factors modestly aligning with each of the threshold concepts outlined in the ACRL "Framework for Information Literacy for Higher Education." As a part of the ongoing development of this instrument, work is needed to more fully assess reliability and validity.