Lets assume your GPA is very high, say 3.95 or higher, at both your undergrad and graduate school institutions. I have always included it while applying to summer research programs and internships while still in my PhD program. But this is probably inappropriate on the postdoc market right?
Perhaps this question is somewhat subjective, but, after checking out some other questions on this exchange, I didn't think it was overly subjective.
Mark Meckes's answer only considers academic postdoctoral positions. In such cases, he is correct: undergraduate and graduate GPA's do not matter.
If you are applying for non-academic postdocs, however, the situation is very different. At large research centers—particularly those managed by corporations, such as essentially the entire US Department of Energy laboratory system—hiring is done by corporate employees, and must be approved by several layers of management. Several of the national laboratories even have strict GPA cutoffs for their employees, regardless of the length of time they've been working post-graduation!
Consequently, if you're applying for positions only in academia, then there's no need to include GPA. However, for anything outside of an academic setting, it can actually help to do so.
No (to the question in the title), and yes (to the question in the post). For postdocs no one cares about your grades. They're only interested in the quality of your research.
