Do France passport holders need a visa to visit LV?

No visa. France is an EU member state and Latvia is an EU/Schengen country, so French nationals enjoy EU freedom of movement and may enter and stay in Latvia indefinitely with just a valid passport or national ID card. A France ordinary passport holder needs no visa to visit Latvia. Both France and Latvia are European Union member states and part of the Schengen Area, so French citizens benefit from the EU right of free movement. They can travel to Latvia carrying either a valid passport or a French national ID card, with no visa, no ETIAS, and no 90/180-day limit. The Schengen 90/180 short-stay rule and the upcoming ETIAS travel authorisation apply only to non-EU visa-exempt nationals, not to EU citizens such as the French. Internal Schengen border controls are normally absent, though they can be temporarily reintroduced; carrying a valid travel document is therefore advisable. For stays beyond three months, an EU citizen exercising free movement may need to register their residence with Latvian authorities, but this is a residence formality, not a visa.