Biochar has been considered a safe soil additive to enhance soil fertility and agronomic traits of different crops. This study was conducted to explore the impacts of sugarcane waste straw biochar on soil characteristics and some agronomic traits of okra. The experiment was carried out with four treatments, i.e., control, sugarcane waste straw biochar (10 ton ha−1), farmyard manure (FYM, 10 ton ha−1), and chemical fertilizers (NPK; 120:100:80 kg ha−1) having three replications of each treatment. Soil samples were tested for texture, bulk density, particle density, pH, electrical conductivity (EC), organic matter content, nitrate nitrogen (NO3-N), and extractable-P. The sugarcane waste straw biochar was characterized for plant major nutrient elements. The impact of various treatments was observed on soils and agronomic traits of okra like plant height, fruit size, fruit length, and yield of okra. Results revealed that sugarcane waste straw biochar expressed higher EC value and noticeable amounts of nitrogen (N), phosphorus (P), potassium (K), sulfur (S), and magnesium (Mg). The sugarcane waste straw biochar, in comparison with FYM and NPK, significantly improved the NO3-N, extractable-P, OM and EC of the calcareous soil, and reduced the soil bulk density. Furthermore, plant growth and yield parameters were significantly improved under biochar application over the control, FYM and NPK. Overall, sugarcane waste straw biochar proved to be a good alternative to conventional organic and inorganic fertilizers under calcareous soil conditions.