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Soil acidity and associated aluminium (Al) toxicity are important constraints to crop production in the acidic hill regions of West Bengal. Liming is widely used to ameliorate soil acidity; however, its effectiveness depends on the rate applied and the interval between lime application and crop establishment. A field experiment was conducted during the kharif seasons of 2023 and 2024 at the Regional Research Station, Uttar Banga Krishi Viswavidyalaya, Kalimpong, West Bengal, to determine a suitable lime rate and application timing for improving soil chemical properties and soybean productivity. Soybean cultivar JS 335 was evaluated using four lime rates (1.5, 3.0, 6.0 and 9.0 t ha-¹) and four application timings (7, 15, 21 and 28 days before sowing) in a factorial randomized complete block design with three replications. Increasing lime rate progressively increased soil pH and reduced soil Al concentration. Soil pH increased with lime application from 5.19 - 5.24 at 1.5 t ha-¹ to 5.89 - 6.27 at 6.0 t ha-¹, while 9.0 t ha-¹ maintained pH values between 6.11 and 6.26. In contrast, soil Al concentration declined from 0.58- 0.46 mg kg-¹ at 1.5 t ha-¹ to 0.34 - 0.23 mg kg-¹ at 9.0 t ha-¹ of lime application. Application timing also influenced soil acidity, with longer intervals between application and sowing generally resulting in greater improvement in pH and reduction in Al concentration at higher lime rates. Soybean growth and yield components, including plant height, seeds pod-¹, 100-seed weight and seed yield plant-¹, generally improved with increasing lime rate up to 6 t ha-1 after which the response became less pronounced at 9.0 t ha-¹. The maximum seed yield (2.40 t ha-¹ and 2.39 t ha-¹) was recorded with 9.0 and 6.0 t ha-¹ of lime application 21 days before sowing. Overall, the findings indicate that liming effectively reduced soil acidity and Al toxicity and improved soybean productivity, with 6.0 t ha-¹ at least 21 days before sowing showing promising potential for acidic hill soils.