The supermodel will file papers at LA County Superior Court as early as next week, sources tell TMZ.
Klum is expected to cite irreconcilable differences as the cause of their split.
The couple, who married in May 2005, have three children together, while Seal adopted Klum's eldest daughter from a previous relationship.
They have renewed their vows every year on the anniversary of their wedding.
Earlier this year, Klum insisted that her marriage to Seal worked so well "because it's real".
"It's a sacred, special moment for us where we tell each other how we feel about each other," she said. "We love each other. We love our kids. We have fun with each other and in all the stages in our lives we go through together."