Background. The demand for psychological services outpaces the number of available providers. Waitlists at mental health clinics range from weeks to months in length, and longer wait-times predict less favorable outcomes once treatment begins. There is a need for efficient, sustainable service models that provide faster access to care. Offering interim, low-intensity supports to treatment-seekers may both strengthen clinically-relevant proximal outcomes and prevent clinical deterioration while waiting for longer-term treatment. Thus, we tested the acceptability and short-term effects of a solution-focused single-session consultation (SSC), offered to individuals waiting for therapy at two outpatient mental health clinics. Method. Clients wait-listed for outpatient therapy at either clinic were offered an SSC. Participants self-reported overall psychological distress at baseline and two-week follow-up, along with levels of hopelessness and perceived agency at baseline and post-intervention. Participants also rated the SSC’s acceptability. Results. Of 90 treatment-seeking individuals offered an SSC, 46 (51.11%) scheduled an appointment, and 30 (65.21%) attended the session (M age = 31.2, 72.67% female). SSC recipients reported significant pre- to post-intervention improvements in perceived agency (d_z = 1.11, p < .001) and hopelessness (d_z = 1.43, p < .001). Psychological distress significantly decreased from baseline to follow-up (d_z = .73, p = .002). Participants rated SSC sessions as highly acceptable, useful, and worth recommending to others. Conclusions. A solution-focused single-session consultation was associated with improvements in hopelessness, agency, and psychological distress in treatment-seeking adults. Pending larger-scale controlled trials, the SSC may help prevent clinical deterioration among individuals on therapy wait-lists.