Question: is the speaker of the house part of the cabinet

Answer: No, The Cabinet includes the Vice President and the heads of 15 executive departments, listed here according to their order of succession to the Presidency. These 15 positions are the core ``cabinet member'' seats, as distinct from other Cabinet-level seats for other various top level White House staffers and heads of other government agencies, none of whom are in the presidential line of succession and not all of whom are Officers of the United States. Note that the Speaker of the House and the President pro tempore of the Senate follow the Vice President and precede the Secretary of State in the order of succession, but both are in the legislative branch and are not part of the Cabinet.