Mrs Tanagada took her oath before the clerk and vowed to represent her people and the country.
Prior to her oath, Prime Minister Rick Hou appointed her as new Minister for Home Affairs.
She entered Parliament after the winning the bye election in May this year.
She defeated former Prime Minister Gordon Darcy Lilo in a landslide victory.
Mrs Tanagada will become the second female Member of Parliament in this current house.
She is a teacher by profession who graduated with a Masters at the University of Waikato, in New Zealand.
Mrs. Tanagada was a teacher at Kukudu Adventist College, Burnscreek Adventist school and Betikama Adventist College before entering parliament.