The EarthLoc Steel Foundation Modular System is comprised of one module (“ESFM”) or a grid of interlocked ESFMs that comprise an EarthLoc Steel Foundation Grid (“ESFG”) design-engineered to support structures that will be subjected to forces from compression, overturning, torsion, sheer, and uplifting. The ESFM is comprised of a Loc-Cylinder, Torsion-Plates, LogLugs and a top-plate, designed to be interlocked with self-aligning LocPlates and/or InterLoc-Pates that conjoin multiple ESFMs to form a grid or array that creates a foundation that will support massive loads in virtually any location or soil composition. ESFMs are installed with a vibratory device with virtually no disturbance to the environment. The components of the ESFM System are removeable and reusable. Cost and installation time is far less than a traditional concrete foundation, is not affected by weather, is environment friendly, and provides a cost effective, practical, and logistically attractive alterative to concrete.