Obsessive relational intrusion (ORI) occurs when someone knowingly and repeatedly invades another person's privacy boundaries by using intrusive tactics to try to get closer to that person. It includes behaviors such as repeated calls and texts, malicious contact, spreading rumors, stalking, and violence (kidnapping and assault).

Drs. Brian Spitzberg and William Cupach, the creators of the term, define ORI as "repeated and unwanted pursuit and invasion of one's sense of physical or symbolic privacy by another person, either stranger or acquaintance, who desires and/or presumes an intimate relationship". Some victims of ORI have no preexisting relationship with or interest in their pursuers; others know their pursuers, but are less interested in making an existing relationship more intimate.