["Journal of Consumer Behaviour, EarlyView. ", "\nABSTRACT\nAligning with social causes has become a prevalent marketing strategy, yet there remains a lack of clarity about how brand‐cause fit—the perceived congruence between a brand and its associated cause—shapes the effectiveness of such initiatives. This research demonstrates that the positive effect of brand‐cause fit on brand credibility is contingent on spatial association: when brand logos and cause messages appear close together, the credibility advantage of high fit diminishes. Furthermore, we identify persuasion knowledge activation as the underlying psychological mechanism that explains how brand‐cause fit influences brand credibility. Study 1A shows that higher fit enhances credibility, while Study 1B replicates the effect using negative message framing. Study 2 identifies spatial proximity as a boundary condition, and Study 3 validates persuasion knowledge as the explanatory mechanism while reaffirming the moderating role of spatial association. These findings contribute to research on spatial association, persuasion knowledge, and brand credibility, while offering actionable insights into the efficacy of cause‐based marketing initiatives.\n"]