The Kotoden Kotohira line (琴電琴平線, Kotoden Kotohira-sen) is a Japanese railway line in Kagawa Prefecture, which connects Takamatsu-Chikkō Station in Takamatsu with Kotoden-Kotohira Station in Kotohira.

It is owned and operated by the Takamatsu-Kotohira Electric Railroad.

The line first opened on 21 December 1926 between Ritsurin-Kōen and Takinomiya.

[1] The line was later extended on both sides to Kotoden-Kotohira and Kawarachō in 1927.

[2] Since the beginning of the 21st century, three new stations have opened: Kūkōdōri on 29 July 2006, Ayagawa on 15 December 2013, and Fuseishi on 28 November 2020.