He is the main character of the The Caves of Steel, The Naked Sun, and the Robots of Dawn. He is talked about heavily in Robots and Empire, which is set several hundreds years after his death.

In The Caves of Steel, he is called to help solve the murder of a Spacer. The Spacers assign to him a robot partner, R. Daneel Olivaw, with whom he becomes a life-long friend. Later, in the Robots of Dawn, he realizes R. Giskard's telepathic abilities long before anyone else does. Giskard modifies his mind to prevent Baley from being able to tell anyone.

Although not explicitly mentioned in the text, from analysis it is possible to determine the years of his birth and his death. He was born in 4679, and died in 4762.

Jezebel Baley was his wife, and Bentley Baley was his son.