Abstract: Industrial agglomeration is a key indicator reflecting the development level of an industry. To promote the high-quality development of China’s marine drugs and biological products industry, this study quantitatively calculated and conducted a cluster analysis on the agglomeration level of the marine drugs and biological products industry in 11 coastal provinces (municipalities) from 2018 to 2024. A driving-force model of “basic resource supply–scientific and technological innovation support–related industry foundation” is constructed, and the driving mechanisms and influencing factors of agglomeration development in key regions are analyzed. Results show that the industrial agglomeration is relatively significant in five provinces: Liaoning, Shandong, Jiangsu, Zhejiang, and Fujian. Based on agglomeration intensity, the 11 provinces (municipalities) can be classified into three types: leading, significant, and general. Specifically, Zhejiang Province exhibits a leading-type agglomeration pattern, Shandong Province shows a significant-type agglomeration pattern, while the other 9 provinces (municipalities) display a general-type agglomeration pattern. Notably, Fujian Province displays a clear trend toward a significant-type agglomeration pattern. Furthermore, three provinces—Zhejiang, Shandong, and Fujian provinces have already established a ternary driving model composed of basic resource supply, scientific and technological innovation support, and related industry foundation. In contrast, three provinces—Liaoning, Jiangsu, and Guangdong provinces remain in a binary driving stage formed by basic resource supply and scientific and technological innovation support. These findings can provide references for coastal areas to further optimize development measures for the marine drugs and bio-products industry.