It is possible to take a day trip from Istanbul to Ephesus when you are visiting Turkey. If you don’t have much time in the country, it is a good way to see both places.
There are daily flights from Istanbul’s airports to Izmir, which is a short distance away from Ephesus. Trains and buses from Izmir to Ephesus arrive at Selcuk, which is within walking distance of the historic ruins.
Alternatively, you can take a taxi or private car, or hire a car to drive from Izmir to Ephesus. If you pre-book a private airport transfer, the price is 45 euros one-way for up to 4 people and 65 euros one-way for 5 or more people.
There are also plenty of package tours that will arrange a day trip from Istanbul to Ephesus with flights and airport transfers. This is one of the easiest and most convenient ways of visiting Ephesus on a day trip.