A field experiment was conducted during the rabi season of the two consecutive years of 2020-21 and 2021-22 at the Horticultural Research Station, Mondouri, BCKV, Nadia, West Bengal to examine the effectiveness of seaweed extract on yield and quality of black cumin. The treatments were composed of 9 different doses of seaweed extract granule soil application, liquid foliar spray and control. Among the 10 treatments, T5 (e.g., SWE granules @4kg ha-1) recorded the highest average plant height of 29.80 cm, 59.45cm and 73.30 cm, at 60, 90 and 120 DAS and the highest number of primary branches (7,10) and secondary branches (24,10) plant-1 respectively at 120 DAS. Similarly, the highest seed yield of 536 kg ha-1 along with different yield attributing characters like the highest mean fresh pod weight (1.40g), dry pod weight (0.36 g) and pod diameter (0.91cm), seed yield plant-1 (2.76g) and 1000 seed weight (2.45 g) were recorded under the treatment T5. The highest B: C ratio (1.97) and highest net return (Rs.52816 ha-1) were also recorded under T5 during the same period of experimentation. From the above experiment, it may be concluded that the soil application of Seaweed Extract in granular formulation @ 4kg ha-1 has a positive influence on growth, yield and quality of black cumin.