To provide a vehicle supply port structure preventing water from accumulating in the structure without interfering with a box component when opening/closing a lid even if the vehicle supply port structure is provided in an inclined portion on a vehicle side surface.

A vehicle supply port structure includes: an opening 106 formed in an inclined portion; a box component (fuel box 110) forming a space recessed from the opening 106 toward the inside; a lid 104 closing the opening 106; and an inclined rotary shaft 124 disposed closer to either of a left side or a right side of the opening 106 so as to open/close the lid 104. The box component includes a first lower surface 118 which is disposed on the rotary shaft 124 side and is inclined downward from the opening 106 toward the inside and a second lower surface which is continuous to an end on an opposite side of the rotary shaft 124 of the first lower surface 118 and is inclined upward from the opening 106 toward the inside. The first lower surface 118 is inclined downward from an end on the rotary shaft 124 side toward the second lower surface.