Dispersal is a complex process that affects all living organisms, with the settlement phase being particularly critical. This phase depends on the interaction between the environmental conditions of the new habitat and the biological traits of both resident and immigrant populations. While these factors have been studied individually, their combined effects remain poorly understood. To address this gap, we conducted an invasibility experiment using the facultatively sexual rotifer Brachionus plicatilis as a model organism. We examined how the combination of migration rates, genetic diversity in the resident population, and the propensity for sexual reproduction in immigrants influence settlement success. Using whole-genome sequencing, we tracked immigrant private alleles to assess settlement. Our results indicate that all three factors –both individually and interactively–, significantly affect settlement success. Specifically, higher migration rates, lower genetic diversity in the resident population, and earlier sexual reproduction in immigrants were all associated with greater settlement success. Notably, high migration rates had the strongest impact when combined with early sexual reproduction in immigrants, while low genetic diversity in the resident population facilitated the settlement of immigrants with delayed sexual reproduction. These findings highlight the importance of considering multiple interacting factors to gain a more comprehensive understanding of dispersal dynamics. They also provide valuable insights into the ecological and evolutionary mechanisms governing the settlement in new habitats with pre-existing populations.