Meaning and Name Origin
Greg \g-reg\ as a boys' name is of Greek origin, and the name Greg means "watchful, vigilant". Greg is a variant of Gregory (Greek): the first of the 16 popes and 10 saints with the name was called Gregory the Great. Somewhat unusual as a given name for boys.
Greg is a very popular first name for males (#174 out of 1220, Top 14%) and also a very popular surname for both adults and children (#22245 out of 88799, Top 25%). (2000 U.S. Census)
Charted below is the baby name popularity of Greg for boys. Greg entered the list in 1940-1949 and reached its top position of #105 in the U.S. during 1960-1969, but is not ranked at the moment. (2014 Birth Statistics)
Displayed below is an analysis of the popularity of the boy name Greg and related names. Prominent alternative forms of Greg appearing in the Top 1000 are Gregg, Greggory, Gregor, Gregorio and Gregory (#316 in 2014). Usage of these boy names reached its peak during the years 1960-1969 and has become significantly lower since, with the versions Greg, Gregg, Greggory and Gregorio becoming less in vogue. Gregory (#316) is the most chic baby name in this compilation. (2014 Birth Statistics)