Oslo to Stockholm or copenhagen
 

Is there an overnight train from Oslo to either of these cities?? Need help asap!

There was an overnight train from Oslo to Copenhagen some years back. I tried to find info online but could not find info on a night train. Have you considered the overnight ferry?

Probably Stockholm; unlikely Copenhagen

For a while the Oslo to Copenhagen train was halted, then brought back I think twice a week during summer. The overnight ferry is lots of fun.

There is definitely an overnight train between Oslo and Stockholm, but I believe the x2000 trains have cut the time down between the 2 cities so significantly as to warrant some consideration of daytime travel.

There is a night train from Oslo to Stockholm run by the Swedish railway company SJ. http://www.sj.se/

There is no night train from Oslo to Copenhagen. In fact there is no direct rail service between teh two cities, you'll have to go by NSB to Gothenburg (http://www.nsb.no/) and there change to a train run by SJ.

As another poster said, there is a boat running overnight from Oslo to Copenhagen. It's a very pleasant way to make the journey. On Fridays and Saturdays this is a party boat, but still suitable for families. One way tickets are often more expensive than two-way "cruise" tickets. You may find that it's better to buy a cruise ticket and then just not go back with the boat when it leaves for Oslo after 7 hours in Copenhagen.

And here is a link to the ferry company running the boat from Oslo to Copenhagen: http://www.dfds.no/

You can also travel overnight by coach from Oslo to Copenhagen on GoByBus or from Oslo to Stockholm on Swebus. You'll find these coach companies and others on http://eurobuslines.info/