According to Official Guinness Records,
The widest tongue measures 8.57 cm (3.37 in) at its widest point and belongs to Byron Schlenker (USA), as measured in Syracuse, New York, USA, on 2 November 2014. Byron Schlenker has previously held this record with a tongue width of 8.3cm, but since this was set, his tongue has become wider! Meet Byron's daughter Emily, who holds the current record for widest tongue (female)
For a complete list of 2014 records, please visit 2014 Guinness Records in United States.