Generally, a citizen of a any country who wishes to visit any foreign country for tourism must first obtain a tourist visa.
So, if you want to visit any foreign country for touristic purposes, you must apply and obtain a tourist visa for that country.
Now, since you did not mention which country you belong to and where you want to go, I would be unable to say specifically if you require it or not. Some countries have agreements with other countries, which allows them to process ‘Visa On Arrival’ and thus you would not need to apply visa before you even catch a flight!