Excel Saga (Japanese: エクセル♥サーガ, Hepburn: Ekuseru Sāga) is a manga series written and illustrated by Kōshi Rikudō. It was serialized in Young King OURs from 1996 to 2011, and its individual chapters were collected and published in 27 tankōbon volumes by Shōnen Gahōsha. The series follows the attempts of Across, a "secret ideological organization", to conquer the city of Fukuoka as a first step towards world domination. The title character of the series, Excel, is a key member of the group who is working towards completing this goal, while the city is being defended by a shadowy government agency led by Dr. Kabapu.

The manga was adapted into an anime television series by Victor Entertainment, which was taglined Quack Experimental Animation (へっぽこ実験アニメーション, Heppoko Jikken Animēshon). Directed by Shinichi Watanabe and featuring animation from J.C.Staff, the series premiered on TV Tokyo in 1999. TV Tokyo only aired twenty-five of the series' twenty-six episodes, with the finale having been intentionally made too violent, obscene and long for broadcast on Japanese TV. As such, it was only included in the DVD release of the series, although it has since been broadcast in other markets.

The series has enjoyed some critical success coupled with respectable sales.