The 2012 Olympic bronze medallist, who defeated North Korea's Kim Hyang Mi in the 48 kilo category, told the Press Trust of India (PTI) news agency she was "really happy" at the way the championship had panned out.
"I would like to dedicate this victory to all those who have supported me even though the world had written me off," said the 34-year-old.
Kom, a five-time world champion, was left heartbroken after she failed to qualify for the Rio Olympics.
The mother of three from a poor family in India's remote northeastern state of Manipur was dubbed "Magnificent Mary" after she won her fifth world championship title in 2010.
She is a member of India's upper house of parliament and was also the subject of a popular Bollywood movie in 2014.
Prime Minister Narendra Modi, who nominated Kom for her parliamentary seat, took to Twitter to congratulate her on her win.
"Congratulations Mary Kom for clinching the gold... India is elated at your accomplishment," Modi tweeted.
Kom told PTI it had been tough to juggle her various roles.
"I don't even know how I manage to pull it off sometimes," she said.