The 28-year-old NY lawmaker is expected to increase scrutiny of big banks, lending and the financial sector when she takes up her new role.
Ocasio-Cortez, a Democratic socialist and the youngest woman ever elected to Congress, has become one of the most prominent members of the new Democratic House majority, pushing for an ambitious progressive agenda and frequently trading social media barbs with conservatives.
Ocasio-Cortez has been a critic of the financial system, and has siad she would like to see the break-up of the biggest banks and the restoration of the Glass-Steagall Act, which separated investment and commercial banking.
The panel will be chaired by Rep. Maxine Waters, California Democrat.
"That doesn't mean all $10 million are taxed at an extremely high rate, but it means that as you climb up this ladder you should be contributing more", she said.
She was originally vying to be on the powerful House Ways and Means Committee, but moderate Democrat Tom Suozzi was selected instead.
She is second only to the president, Axios found, when it measured the Twitter star power of several politicians.
But despite Trump's refusal to even entertain a question about her remark, Ocasio-Cortez seems to be calling it a victory.
Asked at the White House to respond to her, Trump shook his head, waved dismissively and grimaced: 'Who cares?'