A dream journal (or dream diary) is a journal in which dream experiences are recorded. A dream journal might include a record of nightly dreams, personal reflections and waking dream experiences. It is often used in the study of dreams and psychology. Dream journals are also used by people trying to achieve a lucid dream. They are also regarded as a useful catalyst for remembering dreams. The use of a dream diary was recommended by Ann Faraday in The Dream Game as an aid to memory and a way to preserve details, many of which are otherwise rapidly forgotten no matter how memorable the dream originally seemed. The very act of recording a dream can have the effect of improving future dream recall. Keeping a dream journal conditions a person to view remembering dreams as important. Traditionally, dreams have been recorded in a paper journal (as text, drawings, paintings, etc...) or via an audio recording device (as narrative, music or imitations of other auditory experiences from the dream.) Now with the internet, many sites offer the ability to create a digital dream journal.

The discipline of waking up to record a dream in a journal sometimes leads to a false awakening where the dreamer records the previous dream while still in a dream. Some dream journalists report writing down the same dream one or two times in a dream before actually waking up, and recording it in a physical dream journal.

It is important to record the dreams in the journal immediately after waking up, as individuals forget the details of their dreams very quickly after waking up.

Followers of Eckankar frequently keep dream journals, since they view dreams as important teaching tools and as a gateway to "Soul Travel".