Interracial efficacy is critical to intergroup interactions. However, the antecedents of interracial efficacy are unclear and rarely studied from the perspectives of Black individuals. The current work addresses these empirical gaps by testing whether individual differences in suspicion of Whites' motives negatively relate to expected efficacy in interracial interactions. Suspicion was operationalized as beliefs that Whites' positivity toward people of color (POC) is primarily motivated by concerns with appearing prejudiced. Four studies employing correlational and experimental vignette designs with Black adult participants (Ntotal = 2,295; ∼60% female) tested suspicion's hypothesized negative relation with three conceptions of interracial efficacy (general efficacy, liking-based efficacy, and respect-based efficacy). Four studies provided consistent evidence that suspicion of Whites' motives negatively related to expected efficacy in interactions with White social partners. Moreover, this relationship was unique to contexts with White partners and did not extend to imagined interactions with Black partners or members of other outgroup members (e.g., Latine partners). Results further suggest suspicion increases expected threat (i.e., anticipated uncertainty/anxiety), which undermines Black individuals' confidence in interactions with White partners. (PsycInfo Database Record (c) 2024 APA, all rights reserved).