Few studies have examined the relationship between the therapeutic alliance in therapy and suicidal experiences. No studies have examined this relationship with people with non-affective psychosis. The present study sought to redress this gap in the literature. Sixty-four participants with non-affective psychosis and suicidal experiences who were receiving a suicide-focused cognitive therapy were recruited. Self-reported suicidal ideation, suicide plans, suicide attempts, depression, and hopelessness were collected from participants prior to starting therapy. Suicidal experience measures were collected again post-therapy at 6 months. Therapeutic alliance ratings were completed by clients and therapists at session 4 of therapy. Dose of therapy was documented in number of minutes of therapy. Data were analyzed using correlation coefficients, independent samples t-tests, a multiple hierarchical regression, and a moderated linear regression. There was no significant relationship found between suicidal ideation prior to therapy and the therapeutic alliance at session 4, rated by both client and therapist. However, there was a significant negative relationship between the client-rated therapeutic alliance at session 4 and suicidal ideation at 6 months, after controlling for pre-therapy suicidal ideation, depression, and hopelessness. Furthermore, the negative relationship between the client-rated alliance and suicidal ideation was the strongest when number of minutes of therapy was 15 h or below. A stronger therapeutic alliance developed in the first few sessions of therapy is important in ameliorating suicidal thoughts in people with psychosis. Nevertheless, it is not necessarily the case that more hours in therapy equates to a cumulative decrease in suicidal ideation of which therapists could be mindful. A limitation of the current study was that the alliance was analyzed only at session 4 of therapy, which future studies could seek to redress.