Yamazaki Susumu (山崎 烝, c. 1833 – February 6, 1868) was a Shinsengumi officer and spy, otherwise known as a kansatsu (監察, inspector).

In 1863, he officially joined the Shinsengumi and in 1864, Yamazaki and Shimada Kai were assigned by Kondō Isami to investigate the situation which led to the Ikedaya Jiken on July 8.

However, there is a theory that Yamazaki's participation in the Ikedaya Jiken is merely fiction by Shimozawa Kan and Shiba Ryōtarō.

His occupation whilst in Kyoto was as a doctor, and the Shinsengumi had originally used his pharmacy as their base before moving on to its later headquarters at Nishihonganji (See Yamanami Keisuke).

He had Kondo and Hijikata Toshizō's full confidence and was one of the most faithful members of the Shinsengumi till the very end of his life.