The current study examined how the theory of planned behavior (TPB) constructs predict college students’ intent to ask about suicide and refer a potentially suicidal peer to support. Using an experimental design, 420 college students (Mage = 19.61, SD = 1.50 yrs) were randomly assigned to read one of four vignettes depicting a peer in distress that varied suicide risk severity (low vs. high) and perceived causes of the distress (internal vs. external). Participants read their vignette and answered questions measuring TPB constructs and items assessing intent to ask about suicide and intent to refer the peer to services. Results indicated that subjective norms were associated with intent to ask about suicide and attitudes impact intent to refer. Only the interaction between risk severity and perceived behavioral control in predicting intent to refer and intent to ask were significant. Peers who perceive risk to be high are more likely to refer peers regardless of perceived behavioral control and are increasingly more likely to ask about suicide as perceived behavioral control increases. When risk severity is low and perceived behavioral control is low, peers are less likely to refer or ask about suicide. The theory of planned behavior has relevance to understanding peer intent to intervene with an at-risk peer and may be beneficial to guiding the development of effective suicide prevention programs.