There are
2,040 mi
from Oshkosh, WI to Brea, CA
That's the driving distance. It would take 1 day 12 hours to go from Oshkosh, Wisconsin to Brea, California.
The flight distance (direct flight from Oshkosh, WI to Brea, CA) is 1,712.83 mi.
2,040 mi = 3,283.34 kms