Are steam engines still in regular use anywhere in the world?

It is unlikely that steam locomotives will make a serious comeback at any time in the foreseeable future. Firstly, the steam locomotive has a very low thermal efficiency compared to other forms of motive power; secondly, they are enormously labour-intensive, a fact which was of lesser importance when wages were relatively low but is crucial in modern high-wage conditions (this is the main reason why the last major users of steam locomotives were India and China); thirdly, the power output of the locomotive is limited to the ability of one man to feed the firebox (attempts to develop mechanical stokers have met with limited success, primarily because they usually result in a much heavier consumption of coal then with manual firing); fourthly, a steam locomotive cannot simply be turned on and off like an electric or diesel motor and they therefore use substantial quantities of fuel in the lighting-up process (which takes several hours) and when standing idle between turns. It saddens me enormously that this should be the case but there is no use in denying the facts. There are still a few steam locomotives in operation by enthusiasts and long may they continue but, sadly, they can never be anything more than a relic of a bygone age.

From my knowledge, there is a steam engine locomotive still being used in India from Mettupalam to Ooty route. It is always overbooked as many tourists still visit and take the train ride.it is a very pleasant trip and the site through the rail route is very beautiful.

1. Almost every¹ power station that produces electricity uses steam to power its turbines. Only the heat source (of energy): burning fossil fuels like coal, oil, natural gas or using nuclear fission, is different. That is why all power stations are located near a water source, so that they can have unlimited supply of water to heat.

2. There are some steam engines remaining operational in locomotives and boats around the world either for tourist attraction or for the lack of reach of new technology.

^{1. Except the ones using directly renewable sources such as solar, sun and wave.}

The cog railway in NH still uses some steam locomotives to travel back and forth to the summit of Mt Washington. Most have been replaced, but there is still one coal fired locomotive a day that makes the trip

One of the engines on the Welsh Mount Snowdon Railway is a steam locomotive. http://www.snowdonrailway.co.uk/

A large variety of preserved and rebuilt steam locomotives are still used on well over a hundred heritage railways in the UK, some well over 10 miles in length. See the list of British Heritage and Private Railways

On these lines, there are several hundred steam engines regularly used to provide regular timetabled services, especially from March to October, though Christmas 'Santa Specials' are also very popular. Many of the services provide public transport possibilities as well, some of the preserved steam railways connecting with regular train services at junctions and termini. Additionally, there are steam train services run on main lines and even new build and reconstructed express steam engines running for tourist and steam train enthusiasts.

Heritage steam railways play an important part in the economies of many areas in the UK , attracting large numbers of visitors who also use other services locally. For example The small narrow gauge preserved Lynton and Barnstable Light Railway in North Devon, just a few miles long at present, is reckoned to provide a welcome injection of many millions of pounds into the local economy there.

To my knowledge, there is one single cylinder steam engine at the Hook Norton Brewery in England, still working for it's living, and there are several Steam Boats around, such as the Paddle Wheeler Hjejlen in Denmark, and the SS Skjelskoer built in 1915, both are Coal Fired. In Australia there are several Steam Driven Paddle Boats on the Murray River. Most of these are Wood Burners.

Steam Engine:

A steam engine is a heat engine that performs mechanical work using steam as its working fluid.

Unless you are specifically referring to steam railway locomotives, a particular application of the steam engine, then yes steam engines are widely used as the most common worldwide means of producing electric power. The particular class of steam engine most commonly used in this configuration is the steam turbine.

Modern re-invention of the steam railway locomotive is most likely to be considering advanced steam technologies. Use as a replacement for the internal combustion engine for automotive use has also been researched in the recent past.

Research into applications for modern steam engines seems to have been motivated by a fear of drastically higher gasoline and diesel prices for internal combustion and diesel engines. With the recent worldwide supply of shale-oil and shale-gas expected to glut the market for several decades, I expect research into non-stationary steam engines to abate.

Nuclear power stations are steam engines, they just use a different source of energy to generate the steam from what you're probably thinking of.
So yes, steam engines are in widespread use around the planet.