Is Foshan dialect Cantonese?

Yes, and it is the closest to standard Cantonese among all Cantonese sub-dialects. The grading is as follows: Cantonese-Cantonese film-Foshan dialect. Guangdong sea area has the following areas: Guangzhou (including Huadu, Zengcheng and Panyu), Foshan (including Shunde), Hong Kong, Dongguan, Zhongshan, Zhuhai and Jiangmen. Cantonese spoken in Foshan dialect in the above cities is closest to standard Cantonese, second only to Guangzhou and Hong Kong. Only the tone difference does not exceed 15.