<p>Developing high-yielding rice varieties with high nitrogen (N) use efficiency is essential for ensuring food security and the sustainability of rice production. This study aimed to assess varietal differences in grain yield and N utilization and to examine their relationships in single-season hybrid rice. Field experiments were conducted in a subtropical environment of China during 2021 and 2022, involving nine single-season hybrid rice varieties grown with and without N application (180 kg ha^–1). Significant varietal differences were observed in grain yield, total N uptake, internal N use efficiency, N recovery efficiency, and agronomic N use efficiency across both years or in at least one of the years. The variety Longliangyouhuazhan (LLYHZ) exhibited superior performance in grain yield and all N utilization parameters. Across the nine varieties over two years, grain yield with N application was significantly positively related to grain yield without N application, agronomic N use efficiency, and internal N use efficiency. Grain yield without N application was positively related to internal N use efficiency. High grain yield and high N use efficiency can be achieved simultaneously in single-season hybrid rice, with LLYHZ representing a typical variety that exhibits both traits. In addition, this study also indicates that internal N use efficiency plays a crucial role in enhancing tolerance to low-N conditions in single-season hybrid rice.</p>