The 43-year-old woman, identified as Song, made a total of 4,654 prank calls and false alarms between January 2010 and July this year, Dobong district police told the Yonhap news agency.
"I made the prank calls when I was drunk," Song confessed after her arrest.
Song made up a number of fictitious situations, such as finding a corpse or planning imminent suicide, provoking the dispatch of security forces on several occasions, said Dobong police.
South Korean law imposes fines of less than 100,000 won ($95) to those who make such calls.
But it also sets stiffer penalties of up to five years in jail or 10 million won ($9,500) for persistent pranksters or those who cause major damage through telephone calls.