- Real World OCaml, 2nd Ed. - Yaron Minsky, Anil Madhavapeddy, Jason Hickey - 2022 - Practical OCaml: data processing, systems, and web; free online.
- OCaml Programming: Correct + Efficient + Beautiful - Michael R. Clarkson - 2023 - Cornell textbook on FP and data structures in OCaml; free online.
- OCaml from the Very Beginning - John Whitington - 2013 - No-prerequisites introduction with small, progressive chapters.
- Functional Programming in OCaml - Michael Clarkson - 2021 - Course materials; semantics and software engineering with OCaml.