The 49-item Fat Attitudes Assessment Toolkit (FAAT; Cain et al., 2022) is a multidimensional, non-stigmatizing measure of contemporary attitudes towards fatness and fat people, some of which are targeted in stigma reduction research. The FAAT can be administered online or in-person to adults and is free to use. This chapter first discusses the development of the FAAT and then provides evidence of its psychometrics. More specifically, the FAAT has a 9-factor structure within exploratory and confirmatory factor analyses: Empathy (7 items), Activism Orientation (7 items), Size Acceptance (6 items), Attractiveness (5 items), Critical Health (5 items), General Complexity (6 items), Socioeconomic Complexity (3 items), Responsibility (6 items), and Body Acceptance (4 items). Internal consistency reliability, test-retest reliability, convergent validity, and discriminant validity support the use of the FAAT. Next, this chapter provides the FAAT items in their entirety, instructions for administration and scoring, and the item response scale. Logistics of use, such as permissions, copyright, and contact information, are available for readers.