Ed Helms' face tattoo will remain permanent after all ... now that the studio behind "Hangover 2" has struck a settlement with the artist who claims he owns the copyright to the famous design.

Warner Bros. just announced it has "amicably resolved" its dispute with tattoo artist S. Victor Whitmill -- the guy who put the original face tat on Mike Tyson.

Whitmill sued the studio back in April -- claiming WB never asked for permission before they slapped his work on Ed's face ... a gag that proved to be a HUGE plot point in the movie.