I can’t think of any for sure after WWII. Maybe Vietnam or Yugoslavia? Afghanistan?
Officially not since WWII. Unofficially Soviet pilots were operating in Korea using planes marked with North Korean or Chinese markings. Does that count?
I don’t see how Korea can count. Although the North’s view was they were expelling invaders and trying to ‘unify’ one country, the US and most of the rest of the world saw it as the communist DPRK invading the free ROK, two separate countries. Russia was helping the North bomb the South, and we were doing the opposite.
The front moved back and forward several times, at one point pushing almost to the border with China. However you slice Korea up, at certain points Soviet pilots and US pilots would have been both bombing what is now North Korea: the Soviets hitting ROK positions inside what is now North Korea and the US hitting North Korean positions.
The US and Russia are both bombing Syria right now, obviously.
One of the few things that the North and South Korean governments agree on is that Korea is one country. Both governments formally claim sovereignty over the entire country. So the US (officially) and the USSR (unofficially) were both bombing the same country; just different areas within it. And possibly, as the front line moved back and forth, some of the same areas, but at different times.
But the US and Russia do not appear to have the same goal there. The US is targeting ISIS but supporting other rebel groups, while Russia is targeting rebel groups generally.
I think WW2 is going to be the answer - that’s the last time that the US and Russia were bombing the same country (Germany) with the same objective (to beat Hitler).
I think we can safely assume that is why the OP asked the question.
Is it too nitpicky to point out that it was the Soviet Union who were bombing in Korea, Viet-Nam and Afghanistan?
Yes, because WWII was mentioned as an example of what the OP means.
Russie didn’t participate in the NATO air campaigns in the former Republic of Yugoslavia. They did send ground troops for the follow up NATO peacekeeping efforts. A Russian Brigade falling under the tactical control of a US led headquarters (Multi-national Division - North) less than 4 years after the fall of the Soviet Union was pretty surprising. It didn’t involve Russia bombs falling though.
Yes, it is thanks.
It was, but Russia was part of it, so Russia was doing the bombing under that umbrella.
I don’t care about the objective, just that they’re both bombing the same country. So far from the info posted ITT it looks like it was Korea.
Thanks everyone! 
Surely it would be Afghanistan.
Just not at the same time.
Ref List of wars involving Russia - Wikipedia
Assuming you ignore Syria now,
The answer would be Vietnam.
Afghanistan doesn’t count. The us and USSR bombed it at completely different times
Soviet Union had advisers in Vietnam, and they trained North Vietnamese pilots in the Soviet Union, but its not believed that Soviet pilots were actually involved in combat sorties.
It would almost work with China in the late 60’s. There were lots of Chinese military personnel involved in the war effort in North Vietnam who undoubtedly got bombed from time to time, and the US efforts to bomb the supply lines stopped just shy of the Chinese border. At the same time, the Soviet Union fought a bunch of little border skirmishes with China, although I don’t know if any air power was ever involved with those.