Tsugumi Ohba is the pen name of a Japanese manga writer, best known for authoring the Death Note manga series with illustrator Takeshi Obata from 2003 to 2006, which has 30 million collected volumes in circulation. The duo's second series, Bakuman. (2008–2012), was also successful with 15 million in circulation. In 2014, Ohba collaborated with My Little Monster creator Robico for the one-shot "Skip! Yamada-kun". Another series with Obata, Platinum End, was serialized in the monthly Jump SQ from November 4, 2015, to January 4, 2021.

There is significant speculation surrounding Ohba's real identity, with theories suggesting that "Tsugumi Ohba" is a pseudonym for a recognized author. It is believed that the pseudonym might belong to Hiroshi Gamou, known for the manga series Tottemo! Luckyman, or to Yuko Asami, a Shonen Jump artist. Another rumor suggests that the character "L" from Death Note is based on Ohba's personality, especially due to the use of an alias, the love of snacks, and a peculiar way of sitting.

According to VIZ Media's profile, Tsugumi Ohba was born in Tokyo and has a hobby of collecting teacups.