Background: The early identification and diagnosis of autism is critical to ensure access to appropriate early intervention and support. Few studies have examined the association between potentially modifiable characteristics of the service system and timelier diagnosis. Methods: An online survey was conducted to examine parental experiences of service pathways to an autism diagnosis for their child, and to identify child, family, and service level characteristics that predict the age and timeliness of diagnosis. Participants included 107 parents of children with autism who were diagnosed by 7 years of age and a smaller subgroup of 29 parents who were diagnosed after 7 years of age. Results: Parents of younger children reported that, on average, it took approximately 12 months and 8 professional consultations to receive a confirmed diagnosis for their child. Parents of older children, as well as those who reported they were a sole caregiver, or were advised by professionals to 'wait and see', reported more time between first raising concerns and diagnosis. Conclusions: The findings reiterate the importance of proactive professional responses to parental concerns. They also highlight the need for standardised screening and assessment and professional development and training to build capacity in the sector to deliver timely and accurate autism diagnoses.