There isn't, but just few blocks away, in Siget, there's a former First Division and now Second Division team Hrvatski Dragovoljac. Why do you ask?
You have many football clubs from Zagreb: http://en.wikipedia.org/wiki/Category:Croatian_football_clubs Here you can find about all Croatian football clubs. I don't know exact which club represents Zagreb, but I see: NK Lokomotiva NK Lučko NK Croatia Sesvete GNK Dinamo Zagreb NK Dugo Selo NK Dubrava HNK Gorica NK HAŠK NK Hrvatski dragovoljac NK Inter Zaprešić ...etc.
Most people in Zagreb aren't that interested in domestic league (thanks Mamic) but among that list it's probably 99% percent Dinamo.
Yes, I know that Dinamo iz the main club in Zagreb, but didn't knew all of these smaller clubs; do they belong in same district of Zagreb, or are they from some smaller city outside of Zagrebacka zupanija It's borig to click on every club to see in what city he plays. I noticed that NK Zagreb has big changes lately, they signed a contract with Inter Milan, so that Inter can open his camp in Zagreb, better cooperation etc. But I assume that Inter has many camps around the world, so Zagreb for them won't make any difference, when they see situation in Croatian league. Almost nobody watches Croatian league, because it's boring, without any excitement, without money, new stadiums projects. Croatia as a national team don't have their camp, they must go in Slovenia to prepare for matches. Players are mostly in tabloids.