Will I need a visa to travel to the EU post Brexit?
No, if you hold a passport from an EU member state. UK passport holders will not need a visa to travel to Ireland and almost certainly will not need a visa to travel to the Continent either however this is dependant on negotiations during the transition period. The same applies vice versa: holders of Irish passports will not need a visa to travel to the UK; and holders of other EU passports almost certainly will not need one either. Here you can obtain general information on passports before your journey:
The above Q&A is based on latest government advice which may be subject to change.