Double-stranded RNA (dsRNA) biologics used for RNA interference (RNAi)–based agricultural applications offer a powerful strategy for crop protection and trait modification. However, their deployment remains limited by the lack of efficient exogenous RNA delivery systems. While most explored approaches rely on foliar application or carrier-based formulations, we demonstrate that seeds provide an alternative entry point for non-transgenic RNA delivery to plants. Simple seed treatments enable the delivery of both small interfering RNAs (siRNAs) and long dsRNAs into developing seedlings. Both RNA forms enter the seed through the micropyle, migrate to endosperm leucoplasts, move into the radicle’s meristematic region and eventually into aerial plant parts. Despite sharing a common entry route, the two RNA types ultimately attain distinct localisations that can be exploited to achieve different biological outcomes. Seed-delivered siRNAs move into aerial tissues, access the plant cytoplasmic RNAi machinery and trigger silencing of endogenes, resulting in transitive RNAi and visible phenotypes later in development. In contrast, long dsRNAs remain largely unprocessed in the apoplast and available for ingestion by herbivorous insects, triggering host-delivered RNAi for insect pest control. Simultaneous seed delivery of siRNA and long-dsRNA enables dual functionality, combining endogenous plant gene silencing with insect gene knockdown from a single treatment. These findings establish seed-mediated RNA delivery as a simple and scalable platform for deploying RNAi-based crop protection and transient trait modulation without genetic modification.