Ramie (Boehmeria nivea L.) is one of the most important sources of natural fiber. The yield and fiber quality of ramie are affected by mineral nutrients, particularly nitrogen (N), phosphorus (P), and potassium (K). In the present study, we aimed to quantify the influence of N, P, and K fertilizers on growth, yield, and fiber quality of ramie. To this end, ramie plants grown under different fertilizer treatments (no fertilizer, N, P, K, NP, NK, PK, and NPK) were evaluated for differences in plant height, stem diameter, stem fresh and dry weights, number of stems, fiber fresh and dry weights, fiber quality (breaking strength, elongation, and diameter), and total N and P content. Across all fertilizer treatments, NPK, followed by NK, had the greatest significant effect for increasing plant growth, yield, and fiber quality as compared with control plants, whereas P application had the least effect. Plants fertilized with NPK showed strong positive correlations among fiber yield and quality traits with morphological parameters such as plant height, biomass, stem diameter, and numbers of stem. The p correlation of fiber breaking strength with stem diameter (r2 = 0.79), stem biomass (r2 = 0.88), N contents (r2 = 0.91) and P contents (r2 = 0.83) indicated that the combined application of NPK (150, 75,150 kg·ha−1) significantly enhances yield and fiber quality in ramie. Thus, it is suggested that optimum fertilization is important for sustainable ramie production.