Sorry if this has already been addressed, but I couldn't find anything either in this forum or the internet. Is there a mod that allows changing one's character's face mid-game (like in Skyrim)? Also, I seem to remember from playing Oblivion years ago that at one point in the vanilla game it allows you to.

The only point the game allows you to is right before exiting the tutorial sewers. After that, your options are to either use the showracemenu command, which resets your skill and attributes to defaults calculated by the game from your level and race (supposedly there is a way to avoid that but I never got it working) or the best option, use http://www.gamesas.com/topic/1411667-relz-wrye-bash-thread-95/ to import a face from another savegame, or from a file you exported a face to.

If you just want to change your face, the best way to do it is to start a new game, make the face you want (same race), save that game, then exit and use Wrye Bash's Face Import to import the new face.

To change your characters appearance in game without using outside tools:
Open the console, type showracemenu.
Adjust your face as you wish, do NOT click "confirm", as that will reset all your skills and attributes to level 1.
Instead hit ESC while the console is open, save your game in a new slot.
Load the new game.

i just want to confirm what starwing said, so yes, truly no need for additional tools.