Initially conceptualized as a unique personality trait, Sensory Processing Sensitivity (SPS) has increasingly been criticized for its substantial empirical overlap with well-established personality traits such as the Big Five. When accounting for measurement errors, SPS subdimensions even overlap completely with traits such as neuroticism and openness to experiences. A recent study has further indicated a high association between SPS and vulnerable narcissism, but this has only been revealed at a manifest level (Jauk et al., 2023). With this study, we investigated the relationship between SPS, measured by the Highly Sensitive Person Scale, and established personality traits, including the HEXACO personality traits, narcissism, and self-esteem, through a latent variable approach. Using a sample of 1630 participants, latent regression analyses were conducted to explore how the traits mentioned above relate to the three components of SPS: Ease of Excitation (EOE), Low Sensory Threshold (LST), and Aesthetic Sensitivity (AES). Results indicated that neuroticism, openness to experience, and vulnerable narcissism are significantly associated with SPS components, with vulnerable narcissism showing the strongest association with EOE and LST and openness to experience with AES. These findings support the critiques regarding the postulate that SPS is a distinct construct within existing personality frameworks.