A fixing device includes a fixing roller for fixing a toner image transferred onto a sheet and conveying the sheet along a conveyance path, and a separating mechanism for separating the sheet from the fixing roller. The separating mechanism includes a claw member having a tip portion in contact with the outer circumferential surface of the fixing roller to separate the sheet from the fixing roller, a holder member for holding the claw member, and a rotary member rotatably held in the holder member downstream of the tip portion relative to the conveyance path and adapted to guide the sheet separated from the fixing roller to a downstream side along the conveyance path while being rotated. The holder member has a guiding portion for guiding the sheet to the rotary member on the conveyance path between the tip portion of the claw member and the rotary member.