Alva Blanchard Adams Sr. (October 29, 1875 – December 1, 1941) was an American lawyer and Democratic politician from Pueblo, Colorado.

Alva B. Adams was raised and received his early education in Colorado, but for high school he was sent to the Phillips Academy in Massachusetts, where he graduated in 1893.

Throughout his early adulthood, Alva Adams's father remained highly active in politics as a leader of the Colorado Democratic Party.

[3] In 1918, Adams was commissioned as a major in the United States Army Judge Advocate General's Corps, where he served through the end of the war.

[2] In 1920, Adams delivered the keynote address at the Democratic state convention, in which he gave a vigorous endorsement of President Woodrow Wilson and the League of Nations.

[8] Ultimately, Governor Sweet returned to his initial choice, and Adams was appointed United States senator on May 17, 1923.

[11] In 1932, upon the decision of Senator Charles W. Waterman not to seek re-election, Adams ran to succeed him, with Oscar L. Chapman managing his campaign, and narrowly won the Democratic primary over former state Attorney General John T. Barnett.

Waterman died before his term expired, creating a vacancy, but Adams declined to be appointed to the seat and was not a candidate in the special election.

In the early morning of December 1, 1941, he suffered a subsequent heart attack at his D.C. residence at the Park Hotel, which proved fatal.

The Alva B. Adams tunnel is the key component of the largest transmountain water diversion in the state of Colorado—the Colorado-Big Thompson Project (C-BT).

The tunnel runs in a straight line under the Continental Divide from west to east and passing under Rocky Mountain National Park.

The Orman-Adams House in Pueblo, where Alva B. Adams lived from 1918 until his death in 1941, is listed on the National Register of Historic Places.