If I remember correctly, it is located either by your left knee while sitting in the drivers seat on the bottom edge of the dash, or by the side kick plate in the vicinity of the fuse box. Look for a little door to open.
Never fear, the Niro does, in fact, have an OBDII port.
Yup, door by the left knee. Fuses are also there. I leave my Bluetooth OBD reader in there full time. Can't get the door back on with it there, but it is not in line of sight so you would have to really be observant to note a missing panel.
While I have not personally verified the location of an OBDII port INSIDE the vehicle where most other vehicles have it, I DID notice a VERY OBDII looking port UNDER THE HOOD, far right corner. I only noticed this because that is the only place that I could find a benign bracket in which to utilize tie straps to mount and secure a "under the hood" electronic rodent repeller. Yet, thanks to the soy coated wires of the Niro, and most all cars (even NON hybrids) 2008 & later, I had my Niro wire harness chewed just above the fuel pump. Niro out of commission for a week, and $2,300.00 (insurance covered it, NOT Kia warranty, can't expect them to really) Seems that most cars 2008 and later are using soy and corn for wire insulation instead of rubber/plastic, makes for a perfect rodent buffet! Lots of class action lawsuits in the works, but they keep getting settled "out of court" as this kind of recall would make the air bag recalls of recent past pale in comparison given sheer volume of work involved and labor hours. Sorry went off topic there but just provided info in case anyone was wondering why I'm placing an electronic rodent replller under the hood (in the spare tire well as well) and one in the cabin.................