A new high-precision inverse isochron Ar-40/Ar-39 age for the youngest Toba super-eruption is presented: 75.0 +/- 0.9 ka (1 sigma, full external precision, relative to the optimisation model of Renne et al., 2010, 2011). We present the most accurate and robust radio-isotopic age constraint for the Young Toba Tuff. Ar-40/Ar-39 ages for biotite shards harvested from ultra-distal Toba tephra deposits (>2500 km) preserved in archaeological sites in the Middle Son Valley and Jurreru Valley, India, establish provenance with the young Toba super-eruption. The air-fall tephra at these sites can be used as an isochronous horizon facilitating stratigraphic and temporal correlation throughout India. The high-precision Ar-40/Ar-39 age for the young Toba tephra can serve as a tie point for linking of the multiple Greenland ice cores beyond the GICC05 timescale, and permits correlation to other absolutely dated.palaeoclimate archives for the testing of synchronicity in the response of the global climate system.