Limited research exists on fathers' experiences of interparental conflict (IPC) in families with autistic children. We aimed to identify: (1) the extent to which these fathers report IPC across 10 years of child development (4-14 years) and how this compares to fathers of non-autistic children; (2) distinct trajectories of IPC for fathers of autistic children and (3) factors associated with trajectories of IPC among fathers of autistic children. This is a retrospective study using a national dataset. Participants were 281 fathers of autistic children and 7046 fathers of non-autistic children. Although small effect sizes, fathers of autistic children, on average, reported significantly higher IPC when their child was 4-5, 6-7, 8-9 and 10-12 years of age, compared to fathers of non-autistic children. For fathers of autistic children, longitudinal latent class analysis revealed three profiles reflecting 'low and stable', 'moderate and stable' and 'persistently elevated' levels of IPC over time. Regression analysis revealed a range of predictors (e.g. co-parenting support, father age) for fathers of autistic children experiencing 'moderate and stable' and 'persistently elevated' IPC as compared to fathers who experienced low levels of IPC. There is a significant portion of fathers of autistic children who experience ongoing and heightened IPC, highlighting the need for targeted support.