<p>This study presents a new astro-geodetic deflection of the vertical (DoV) dataset for the Netherlands, combining previously unpublished measurements from the digital zenith camera system TZK2-D with historical visual observations spanning more than a century. The TZK2-D observations have estimated accuracies ranging from 0.03″ at the <i>‘Sonnenborgh’</i> observatory in Utrecht to less than 0.1″ at the remaining stations and are in good agreement with independent historical visual observations. No statistically significant differences were detected (<i>α</i> = 0.05), confirming the high quality of both datasets. The combined dataset enables a quantitative comparison with the high-resolution gravimetric quasi-geoid model for the Netherlands. Using a tailored Least Squares 2D Bi-Cubic Spline Approximation (LS-BICSA), gravimetric DoVs were computed from the gridded quasi-geoid model. The observed and computed values (<i>ξ</i>, <i>η</i>) agree at the 0.2″ level (overall weighted RMS), which is an excellent result considering observational, model, and interpolation errors. Based on the distribution of standardized residuals, a mean standard error of approximately 0.08″ was derived for DoVs computed from the gravimetric quasi-geoid model, consistent with independent variance–covariance analysis. These findings underscore the enduring scientific value of both historical and modern astro-geodetic observations for the evaluation of quasi-geoid models.</p>