A document display device includes a controller. The controller controls a display for displaying document data constituted by plural pages. The controller controls the display to display pieces of content of at least two consecutive pages of the document data side by side and to display one or more of content-displayed pages, which are the pages for which the pieces of content of the pages are displayed side by side, and one or more of pages other than the content-displayed pages among the plural pages so as to overlap.