1x01

1x01 is a television episode designation used to indicate the first episode of a show's first season. The format is widely used in online episode guides, databases, and fan wikis as a compact label that can accompany the title. It is part of a broader family of numbering schemes that help viewers and researchers track air dates, production order, and narrative continuity.

The standard reading is season number, an "x", and episode number, for example 1x01 for season 1, episode 1. Some guides or catalogs pad numbers with leading zeros (1x01 vs 01x01), or use an alternate format such as S01E01; the choice often depends on the site or production company. The 1x01 label usually corresponds to the premiere episode of season one, and is frequently, but not always, the introduction to the show's premise. In many series the pilot is labeled as 1x01, while production codes may differ and appear separately in official documentation.

In practice, 1x01 is primarily a cataloging convenience. It does not always reflect the order in which episodes were produced or aired, since production order and broadcast order can diverge for various reasons, including special premieres, two-part episodes, or schedule changes. For researchers, subsequent references may use multiple formats (S01E01, 1x01, or 1x01-01). See also episode numbering, production codes, and pilot episodes.