There are 109 playable characters in Genshin Impact as of Version 6.2 "Luna III" (released December 3, 2025).
This total comes from the official Genshin Impact Fandom wiki's Character List and main Character pages, which explicitly state "There are 109 playable characters" and confirm it via a full table of entries (counting the Traveler as one entry despite their dual forms: Aether/Lumine). It includes all characters obtainable through wishes, events, or other means up to the latest releases, such as Nefer (Version "Luna II," October 2025), Flins and Lauma (Version "Luna I," September 2025), and earlier additions like Durin and Jahoda from the current Version 6.2 Phase 1.
Breakdown by obtainability (from the wiki):

Non-Wish characters (3): Aloy, Traveler, Wonderland Manekin.
Event Exclusive (50): Limited banner characters like Arlecchino, Furina.
Standard Wish (3): Always available like Amber, Kaeya, and Lisa.
The rest are standard or chronicled wishes obtainable.

The above content is compiled by ModeZone, a fashion and entertainment magazine.