The short answer is no, but that would be a bit untruthful since I think what you mean is something else (if not, I apologize):

Oktoberfest is not a pan-German phenomenon, it isn't even a pan-Bavarian (whose culture seems to be often associated with Germany in General abroad) one. Oktoberfest is a Munich tradition, it originated in Munich as a celebration of the marriage between King (then crown-prince) Ludwig I. of Bavaria and princess Therese of Sachsen-Hildburghausen (a minor Ernestine duchy). The Theresienwiese, where Oktoberfest takes place, is named after her.

So you'd be hard pressed to find Oktoberfest celebrations held anywhere outside Munich in the FRG as well, especially in the North. There are copycat 'Oktoberfest' celebrations throughout Germany nowadays, but those piggyback on the popularity of the Munich event.

Now, with that in mind, there are a lot of Volksfeste (literally 'people's festivals', usually a combination of beer or wine festivals, depending on local customs, and carnival) throughout Germany (more than 10.000 a year), and they have a long history going back to the Middle Ages. I'm not a mediaevist, so I'm not going to embarass myself talking about that stuff, but I'll point out that there is a current initiative to have the German Volksfeste accepted into the UNESCO world cultural heritage for the importance they hold in German culture, which tells you a lot about how important they are for many Germans and the communities where they are held. Here is an English language article on the topic. There are many famous other 'Fests', like the Cannstadter Wasen in Stuttgart, the Hamburger Dom and so on. You'll find them even in small cities and villages, accordingly smaller in scale.

This means, of course, that they were also important for people in the GDR. The leaders of party and state also recognized the role they could play in pacifying and appeasing the population, by providing pleasures and distractions (often by also providing music or products that were not commonly available), while also recognizing the danger that masses of people under alcohol could pose should the mood turn against the system. Thus members of the security organs were usually present, even if attempts to ideologically take over these festivals to instrumentalize them for propaganda were not really successful on a grand scale.

I don't know if there are any English language sources on this topic, but 'Die heile Welt der Diktatur: Alltag und Herrschaft in der DDR 1971-1989' by Stefan Wolle is a good source for everyday culture in the GDR.

This page has some pictures of Volksfeste/Jahrmärkte in the GDR and some of the attractions you might find there:

http://walzerbahn.de/volksfest-ddr.html

Here's also a map (from 2010) showing the locations of copycat Oktoberfests throughout Germany:

http://images.zeit.de/lebensart/2010-09/d-karte-37/d-karte-37-thickbox.jpg

There you'll also see that, apart from the one in Berlin(West) 1949, this trend as a mass-phenomenon is a pretty new one, taking off really only after the fall of the GDR and in time-periods of which we do not speak here.