An image forming apparatus includes a sheet feed portion configured to feed a sheet, an image forming portion configured to form an image on the sheet, a first conveying path configured to guide the sheet fed from the sheet feed portion such that the sheet passes through the image forming portion, a second conveying path configured to guide the sheet on which the image has been formed on one surface thereof by the image forming portion to the first conveying path again, a document feed portion configured to feed a document to the second conveying path, an image reading portion configured to read an image of the document fed by the document feed portion, and a control portion configured to control the sheet feed portion and the document feed portion such that the document and the sheet are conveyed on the second conveying path in a sequence in which the document and the sheet are mixed in a case where an operation of forming images respectively on both surfaces of a plurality of sheets overlaps with an operation of reading images of a plurality of documents.