According to our friends at https://thehempoilbenefits.com:

CBD Oil which contains CBD as main ingredient is extracted from Hemp Plants with a concentration of THC lower than 0,2 %.

The following list is a list of countries that we know does allow CBD Oil from Hemp:

United States, Argentina, Austria, Belgium, Belize, Brazil, Bulgaria, Canada, Chile, China, Colombia, Costa Rica, Croatia, Cyprus, Czech Republic, Denmark, England, Estonia, Finland, France, Georgia, Germany, Greece, Guam, Guatemala, Hong Kong, Hungary, Iceland, India, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Netherlands Antilles, Northern Ireland, Norway, Paraguay, Peru, Poland, Portugal, Puerto Rico, Romania, Russia, Scotland, Slovak Republic, Slovenia, South Africa, Sweden, Switzerland, U.S. Virgin Islands, United Kingdom, Uruguay, & Wales.

If you do not live in one of these countries, CBD Oil extracted from a Cannabis Sativa Variety with a THC content less then 0,2% (Hemp) may be not illegal. But  you should inform yourself about the law in your country before ordering.