Social justice movements often consist of both targets of bias (e.g., Black people) and nontarget allies (e.g., White people). However, little is known about what factors shape minorities’ perceptions of allies and their ally behaviors. Across four studies, we investigated Black participants’ perceptions of Whites’ motives to engage in ally behaviors. In Study 1, we found that Black participants perceived nontarget allies as both highly internally and externally motivated, suggesting ally motives may be ambiguous to Black perceivers. Studies 2–4 examined the effect of Black participants’ suspicion of Whites’ motives on perceptions of White allies’ sincerity and support for their ally efforts. As predicted, suspicious Black participants perceived White ally protestors, confronters, and political candidates as less sincere than similar Black targets and, in turn, were less supportive of White allies’ efforts. Discussion focuses on how perceived motives of White allies impact perceptions of allies and their ally efforts.