Fear, particularly the “fear of weight gain” is central to the diagnosis of various eating disorders (EDs), including Anorexia Nervosa (AN), Atypical Anorexia Nervosa (AAN), and Bulimia Nervosa (BN) (Steinglass et al., 2013). Strober’s (2004) theoretical framework proposed that anxiety-related behaviors in AN may reflect an abnormality in fear learning, such that individuals with AN are more prone to learn associations (“fear acquisition” in the present study) than those without AN. This framework is also relevant for AAN and BN, as they share similar fear-related mechanisms that may influence behavior. The primary fear conditioning paradigm consists of four phases known as “acquisition”, “generalization”, “extinction”, and “renewal” (McGregor et al., 2022). Fear acquisition refers to the process of fear learning resulting from the repeated pairing of a stimulus with an aversive unconditioned stimulus (US), which is referred to as fear acquisition training (Lonsdorf et al., 2017). Fear generalization assesses how fear learning transfers to stimuli with similar perceptual (stimuli that are neutral but perceptually similar to conditional fear stimuli) or conceptual (stimuli that are categorically related to a conditioned stimulus (CS) even though perceptually distinct) properties (Bennett et al., 2015). Fear extinction refers to the reduction of conditioned fear responding as a result of repeated CS presentations in the absence of the US and is a central mechanism of exposure-based treatments (Pittig & LeBeau, 2018). Fear renewal represents the return of fear when an individual encounters contexts or cues outside the setting where extinction learning occurred (Pittig et al., 2018). However, fear conditioning research among ED populations is preliminary. For instance, Lambert (2021) found no significant group differences between AN and control groups during the acquisition phase, but AN groups had greater threat expectancy during the extinction and renewal phases. Thus, fear learning in the context of EDs remains a new area of exploration, with only one study to date examining fear conditioning specifically in ED samples. Given the relevance of anxiety and fear in the EDs and to the application of exposure therapy to EDs, more research is needed. In the present study, we will explore the relations between each phase of fear learning and ED pathology, eating-related fears, and anxiety comorbidities. A smartphone application, the Fear Learning and Anxiety Response (FLARe) app, was used to deliver the fear learning procedure remotely via smartphone. FLARe measured: fear acquisition (i.e., initial pairing of a US with a negative CS), fear extinction (i.e., extinguishing the fear association), fear generalization (i.e., generalization from CS to other similar stimuli), and fear renewal (i.e., reacquisition of fear association after extinction). During fear acquisition, participants viewed 12 presentations each of a large and small circle on a background image of an outdoor scene (Context A). A human scream was used as the US) and paired with 75% of the presentations of one of the two circles serving as the CS). The circle paired with the scream was counterbalanced between participants and became the CS+ (associated with threat) while the circle never paired became the CS− (associated with safety). During generalization, one presentation of the CS+ was paired with the aversive stimulus. Fear extinction consisted of 18 presentations each of the CS+ and CS− on a background image of an indoor living room scene (Context B) with no US. Fear renewal involved four presentations each of the CS+ and CS− on Context A with no US. FLARe includes two primary outcome measures: expectancy and affective ratings. Expectancy ratings capture participants' anticipation of a scream during each trial of the CS presentations, assessing how strongly they expect the aversive event to occur. Affective ratings gauge participants' emotional responses to each stimulus at four time points: before the experiment (baseline), after acquisition (post-acquisition), after extinction (post-extinction), and after renewal (post-renewal). While a wealth of literature has explored the relation between eating and body-related fears, anxiety comorbidities, and eating disorder pathology, the role of fear learning is largely unexplored. Investigating the role of fear learning in eating disorders is crucial for several reasons. First, understanding the correlations between fear learning and ED pathology could provide insights into why those with EDs may be more sensitive to weight-related cues and perceived threats around food. Second, understanding fear learning could clarify links between eating disorders and anxiety disorders, which creates opportunities to identify specific targets for therapeutic intervention. Finally, understanding fear learning could uncover pathways that contribute to the onset of EDs by identifying individuals at risk and intervening before maladaptive eating behaviors become entrenched. The present study will explore how fear learning relates to eating disorder pathology, eating and body-related fears, and anxiety comorbidities, within a clinical eating disorder sample. Thus, the present study represents a step forward in understanding how fear learning mechanisms contribute to the complexities of eating disorders, potentially informing more effective prevention and treatment strategies.