Dimitar Nikolov Asenov (Bulgarian: Димитър Николов Асенов) (10 May 1840 – 10 August 1868), better known as Hadzhi Dimitar (Хаджи Димитър), was one of the most prominent Bulgarian voivods and revolutionaries working for the Liberation of Bulgaria from Ottoman rule.
Dimitar was born in Sliven to the family of the merchant Nikola Asenov and his wife Marinka Asenova. When he was two years old, his family went on a pilgrimage to Jerusalem, from which point onward, Dimitar was considered to be a hajji (хаджия). During Hadzhi Stavri's Uprising of 1862 Hadzhi Dimitar wandered through the Balkan Mountains with a band of revolutionaries for the whole summer.
He joined the band of Stoyan Voyvoda in 1864 as a standard bearer. The band consisted of twelve people and was formed after the murder of the Greek bishop of Veliko Tarnovo. However, it disbanded before entering the city and its members separated from their leader. Hadzhi Dimitar assumed command and led the band into the Balkan Mountains near Sliven and then to Romania in August.
Another band was formed in the home of Georgi Sava Rakovski on 21 May 1865. Among its members were Hadzhi Dimitar, Stefan Karadzha, Yurdan Yurdanov, Petar Shivarov and Todor Shivarov. The band crossed the Danube near Silistra on 13 June and headed for the mountains near Kotel through the Ludogorie. It was active in the region of the Tundzha, Tvarditsa, Karlovo, Gabrovo and the well-known hajduk gathering place Aglikina Polyana. This band returned to Romania in August 1865.