The EU has a common visa policy for short stays (up to 3 months), which is applied through the Schengen visa scheme.
Generally, a short-stay visa issued by one of the Schengen countries entitles its holder to travel throughout the 26 Schengen countries for up to 90 days in any 180-day period. Turkey is among the countries for which that visa is required.
Turkish visa policy is largely aligned with the EU policy. However, Turkey’s policy includes third countries whose nationals must be in possession of visas when crossing the external borders (see European Parliament legislative resolution of 2 October 2018). This puts an additional layer of complexity on EU-Turkey relations for harmonisati on of the visa lists. The EU launched the Visa Liberalisation Dialogue with Turkey in December 2013.
Information about visas for travelling into Turkey is available through this Turkish government webpage.