Synchronicity is a term used by the Swiss psychologist Carl Jung to describe the alignment of universal forces with one's own life experience. Jung believed that some, but not all, coincidences were not mere chance, but instead a literal "co-inciding", or alignment of forces in the universe to create an event or circumstance. The process of becoming intuitively aware and acting in harmony with these forces is what Jung labelled "individuation." Jung said that an individuated person would actually shape events around them through the communication of their consciousness with the collective unconscious.

Jung spoke of synchronicity as being an acausal connecting principle, in other words a pattern of connection that works outside of or in addition to causality.

Jung's most well-known example of synchronicity involves plum pudding. He tells a tale of a certain Monsieur Deschamps who is treated to some plum pudding by his neighbor Monsieur de Fortgibu. Ten years later, he encounters plum pudding on the menu of a Paris restaurant, and wants to order some, but the waiter tells him the last dish has already been served to another customer, who turns out to me M. de Fortgibu. Many years later, M. Deschamps is at a gathering, and is once again offered plum pudding. He recalls the earlier incident and tells his friends that only M. de Fortgibu is missing to make the setting complete, and in the same instant the now senile M. de Fortgibu enters the room by mistake.