पत्र, चिट्ठी या खत किसी कागज या अन्य माध्यम पर लिखे सन्देश को कहते हैं। उन्नीसवीं एवं बीसवीं शताब्दियों में पत्र ही दो व्यक्तियों के बीच संचार का सबसे विश्वसनीय माध्यम था। किन्तु अब टेलीफोन, सेलफोन एवं अन्तरजाल के युग में इसकी भूमिका काफी कम हो गयी है।पत्रो का हमारे जीवन में एक महत्वपूर्ण स्थान है। पत्र संचार का एक सुगम साधन है।

A letter is a written message conveyed from one person to another through a medium. Something epistolary means that it is a form of letter writing. The term usually excludes written material intended to be read in its original form by large numbers of people, such as newspapers and placards, although even these may include material in the form of an "open letter". The typical form of a letter for many centuries, and the archetypal concept even today, is a sheet of paper that is sent to a correspondent through a postal system. A letter can be formal or informal, depending on its audience and purpose. Besides being a means of communication and a store of information, letter writing has played a role in the reproduction of writing as an art throughout history. Letters have been sent since antiquity and are mentioned in the Iliad. Historians Herodotus and Thucydides mention and use letters in their writings.