The 55th Speaker of the House Nancy Pelosi (D-California).
The House of Representatives of the 116th Congress has 235 Democrats and 199 Republicans. There is one open seat -- the 9th District of North Carolina. This gives the Democrats a current advantage of 36 seats (votes).
From Vox.com, here are 10 new Democratic committee chairs who will provide oversight of the Trump administration:
Intelligence Committee — Adam Schiff (D-California)
Oversight Committee — Elijah Cummings (D-Maryland)
Judiciary Committee — Jerry Nadler (D-New York)
Ways and Means Committee — Richard Neal (D-Massachusetts)
Financial Services — Maxine Waters (D-California)
Foreign Affairs Committee — Eliot Engel (D-New York)
Energy and Commerce — Frank Pallone (D-New Jersey)
Natural Resources — Raúl Grijalva (D-Arizona)
Veterans’ Affairs — Mark Takano (D-California)
Science, Space, and Technology — Eddie Bernice Johnson (D-Texas)