Perilla is a traditional oilseed crop cultivated in Korea. The ‘Nulsaemi’ cultivar was developed for oil use because of its large seed size and high functional compound content. It originated from a cross between ‘Daesil’ (IT274265), with high crude fat content and a soft seed coat, and ‘Milyang16’ (K015415), with large, brown seeds and a hard seed coat. The cross was created in 2008, and promising lines were selected through pedigree breeding up to the F₆ generation. Advanced yield trials were conducted in 2016 and regional yield trials were conducted at four sites (Milyang, Suwon, Cheongju, and Iksan) from 2017 to 2019. ‘Nulsaemi’ matures around October 8, which is slightly later than the standard cultivar ‘Dayu’. It also has a 1,000-seed weight of 5.2 g, which is 1.4 g heavier than ‘Dayu’. The seed hardness was low, making it suitable for processing. The average yield was 125 kg/10a, about 3% higher than that of ‘Dayu’. The seeds contained approximately 45.1% crude fat and 63.4% alpha-linolenic acid, similar to those of the standard cultivar. However, rosmarinic acid content was significantly higher at 2,130.6 μg/g, about 18% more than ‘Dayu’. In sensory evaluation, oil extracted from ‘Nulsaemi’ showed better appearance, aroma, taste, and overall preference compared to the control, in both cold-pressed and roasted oil types. ‘Nulsaemi’ is expected to be a high-quality oilseed cultivar suitable for premium perilla oil production (Registration No. 8792).