An ink supply device includes a reservoir; an ink carrying rotary member; a supply rotary member that rotates and supplies ink to the ink carrying rotary member while a part thereof is immersed in the ink in the reservoir; a regulation member that faces an outer peripheral surface of the supply rotary member, the regulation member regulating an amount of ink on the outer peripheral surface of the supply rotary member at a position outside of the reservoir; and a blocking member that extends from below to above a liquid surface of the ink in the reservoir at a position between a landing position and the supply rotary member, the landing position being a position at which ink that has been scraped off by the regulation member lands on the liquid surface, the blocking member blocking movement of the ink from the landing position to the supply rotary member.