5 prototypes built in 1937.
Was the first of the series to be produced and was based on the PzKpfw III Ausf E.
Has the same suspension, drive train, components, and basic hull shape as the PzKpfw III Ausf F. There were no escape hatches on the hull sides. The 75 mm gun was offset to the right and the driver was provided with a pivoting visor, a twin periscope in the superstructure front, and a vision port in the left superstructure. The gunner had an artillery type periscope and had a vision port in the left superstructure. The commander had a scissors periscope which could be raised by opening the front half of his roof hatch.