The present study aims to assess genetic variability for agronomic characters in the interspecific population developed by hybridization between Sesamum indicum (Swetha til) x Sesamum mulayanum (IC-43144-1). Experimental materials were raised during late Kharif-2023 at ICAR-Indian Institute of Oilseeds Research, Hyderabad. A total of 80 F6 interspecific derivatives were evaluated along with four check varieties namely GT-10, Swetha Til, IC-43144-1 (S. mulayanum), CUMS-17 in Augmented Randomised Complete Block Design (ARCBD). Analysis of variance (ANOVA) revealed, significant variability in the interspecific derivatives for all the traits studied viz., days for emergence, days for flowering initiation, days for flower session, days for maturity, plant height, number of primary branches per plant, total number of capsules per plant, capsule length, test weight, harvest index and seed yield per plant. The magnitude of phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) values were higher for the traits viz., total number of capsules per plant, harvest index, seed yield per plant, hence improvement through selection could be possible. Phenological traits such as days for emergence, plant height, number of primary branches per plant, total number of capsules per plant, harvest index and seed yield per plant exhibited a high heritability along with a high genetic advance as per cent of mean, indicating additive gene action in the expression of these traits. Simple phenotypic selection may be effective for improving these characters. So, the selection based on these traits should be prioritized in the selection process of interspecific hybrids of sesame breeding programme.