Theory of Love (Thai: Theory of Love – ทฤษฎีจีบเธอ) is a 2019 Thai BL television series starring Atthaphan Phunsawat (Gun) and Jumpol Adulkittiporn (Off).

Directed by Nuttapong Mongkolsawas and produced by GMMTV, the series was one of the thirteen television series for 2019 launched by GMMTV in their "Wonder Th13teen" event on 5 November 2018.

[3][4] The story is about third year film student Third (Atthaphan Phunsawat) who has feelings for his friend Khai (Jumpol Adulkittiporn) for three years with a result of painful unrequited love.

But when Third decides to move on, Khai incidentally realizes that he also has feelings for Third.

Below are the cast of the series:[5][6] On 26 October 2020, GMMTV announced a special episode of the said series with the title "Stand By Me" which aired on 28 October 2020.