text: which president served the least/most time in office? i love trivia.   president who served the least time?  presidents who served the most time??  winner gets??  you guessed it! 10 points for being the best answer! franklin deleno roosevelt served the most time in office: he was elected 4 times, each a 4 year span!  though he died about a year after he was elected for the 4th time, he holds the record.  after he got the american people through the great depression, they just couldn't get enough of him!  william harrison served the least--upon inaguration, he gave the longest speech ever, without a coat, and caught the chill.  he had less than a month to be commander-in-cheif!