Musical training likely has a positive impact on executive functions (EFs) and quality of life (QoL). Although enhanced musical ability has been observed in the autistic population, research suggests that autistic traits are associated with worse EF and QoL in both the general and autistic populations. It remains unclear whether autistic traits within the general population are related to better musical abilities, and how that might interact with their EF and QoL. The current study aimed to examine musical sophistication and its relationship with EF, QoL, and autistic traits. One hundred seventy (129 females; Mage = 20.5) university students completed the Goldsmiths Musical Sophistication Index, the Adult Executive Functioning Inventory, the Autism Spectrum Quotient, and the Pediatric Quality of Life Inventory General Core Scales for adults. Although no significant association was found between musical sophistication and autistic traits, musical sophistication was associated with fewer EF difficulties. Moreover, participants with more autistic traits and more EF difficulties tend to have a lower QoL. These effects remained significant after controlling for key demographic variables. EF mediates the effect of musical sophistication on QoL; greater musical sophistication is related to better EF and, in turn, better QoL. When looking into the subscales of the Goldsmiths Musical Sophistication Index, having fewer EF difficulties were linked to better Emotions, Musical Training, and Perceptual and Singing Abilities. Our results offer insights into how musical sophistication is related to EF, autistic traits, and QoL.