An image reading apparatus includes a conveyor. The conveyor is configured to convey a first medium in a first conveyance direction along a first conveyance path and a second medium in a second conveyance direction along a second conveyance path. The image reading apparatus includes a reader. The reader is configured to read image data from the first medium and the second medium. The image reading apparatus includes a movable guide. The movable guide is disposed on a housing of the image reading apparatus. The movable guide is configured to be moved to regulate a width of the second opening defined in a direction perpendicular to the second conveyance direction.