Merlin Studios artists started working on the figure in late December, the museum said.
Obama will be the third first lady immortalized in wax by Madame Tussauds' Washington facility, joining Jacqueline Kennedy and Secretary of State Hillary Clinton.
"As our nation's first African-American first lady, a proud working mom and a budding style icon, Mrs. Obama is a role model to women around the corner, and around the globe," Janine DiGioacchino, general manager of Madame Tussauds in New York and Washington, said in a statement.
"Artists at Merlin Studios in London have been busy studying hundreds of photos and watching hours of video footage to create Mrs. Obama's figure," the museum said in a news release. "The clay head mold represents a crucial step in the up to six month-long figure creation process, which is incredibly intricate. Artists insert each strand of hair individually; creating just the head of the wax figure can take up to five weeks alone. Materials such as red silk are used to create the veins on the eyeballs and it can take technicians almost four days to make a set of teeth."
Michelle Obama's figure will join President Barack Obama's figure in the attraction's replica of the Oval Office.