Behavioral and neural correlates of response inhibition are assumed to relate to impulsivity and compulsivity, but findings are inconsistent, possibly due to prior research studying these dimensions in isolation. Negative urgency, the tendency to act impulsive under negative affect, and compulsivity relate to various mental disorders and are assumed to reflect deficits in inhibitory control. However, few studies have examined how response inhibition relates to negative urgency, compulsivity, or their interaction. To address this gap, we conducted a comprehensive analysis of the behavioral and neural correlates of response inhibition and their associations with negative urgency and compulsivity. We examined 233 participants who performed a stop-signal task while electroencephalography was recorded. The analysis involved single-trial regression and latency analyses to explore the relationships with self-reported negative urgency and compulsivity. Stop-signal reaction times (SSRTs) and negative urgency were associated with an attenuated P3 effect contrasting successful stop versus go trials. Crucially, longer SSRT was associated with reduced P1 amplitudes (on successful and failed stops) and a later onset and peak of the P3. Interestingly, the opposite pattern was observed for higher negative urgency with higher P1 amplitudes and an earlier P3 onset and peak in successful stop trials. Associations with compulsivity were not observed. Considering early sensorimotor processes and latency effects are important to capture differences between negative urgency and SSRT. Higher stop-signal-related P1 amplitudes and a faster action cancellation process may compensate reduced P3-related activity in high negative urgency.