Is the speaker of the house a member of the majority party?

No.

Article I, Section 2 of the U.S. Constitution states, "The House of Representatives shall choose their Speaker and other Officers."

It doesn't state that they must be a member. However, all Speakers to date have been Members.

When a newly elected Congress convenes for the first time, the major party nominates a candidate for Speaker. Members elect the Speaker by roll call vote. A Member usually votes for the candidate from his or her own party, but can vote for anyone, whether that person has been nominated or not.

At the moment, the Republicans control the House of Representatives, and the Speaker of the House is Republican John Boehner of Ohio. He replaced Democrat Nancy Pelosi at the first session of the 112th Congress, in January 2011.