Recovery of coral reefs is reliant upon the recruitment of coral larvae, yet the mechanisms behind coral larval settlement are not well understood. Biofilms associated with reef substrates, such as coral rubble or crustose coralline algae, have been shown to induce coral larval settlement. However, the biochemical cues and the bacteria that produce them remain unknown for most coral species. Here, we conducted coral larval settlement assays with five non-acroporid coral species, using biofilms pre-conditioned for either one or two months under light and dark treatments. Biofilms were characterised using shotgun metagenomic sequencing to identify the taxonomy and metabolic pathways associated with inducive and inhibitory biofilms. We show that light and biofilm age are critical factors in the development of settlement inducing biofilms. These biofilms are highly diverse with over 700 metagenome assembled genomes recovered, which encode a broad variety of functions including the production of secondary metabolites. Further, distinct changes in biofilm composition were observed between conditioning treatments that were associated with high or low settlement. Hence, by identifying the key species necessary for biosynthesis of settlement inducing metabolites, we can target microbial inducers of coral settlement for cultivation to improve coral aquaculture and reef restoration.