Willis also lost her associate economic development portfolio in the recent reshuffle.
She will take climate change spokesman Stuart Smith's place on the environment committee. Smith will also go to finance and expenditure, replacing Michael Woodhouse.
Woodhouse will replace Chris Bishop on the privileges committee.
Bishop will sit on the health committee, replacing Matt Doocey. Bishop will also sit on the regulations review committee, replacing Penny Simmonds.
Bishop's other select committee role, the standing orders committee, will now be taken by deputy shadow leader of the house Simeon Brown.
Mark Mitchell will replace Harete Hipango on the justice committee - Hipango will move to the Māori affairs committee, replacing Todd Muller.
Muller will sit on the petitions committee, replacing Tim van de Molen.
Van de Molen and new transport spokesman David Bennett will both join the transport and infrastructure committee.
Overall, the select committee reshuffle moves the caucus' liberal MPs to less powerful and less high profile committees.
In the case of Muller, the move is to be expected. Retiring MPs are often shuffled into less high profile roles.
Moving Willis from finance and expenditure is a significant step, given the committee's prominence, influence, and power.
Bishop's relative demotions are to be expected. His previous select committee positions were commensurate with his role as shadow leader of the house.