Harold Royce Gross (June 30, 1899 – September 22, 1987) was a Republican United States Representative from Iowa's 3rd congressional district for thirteen terms.

The role he played on the House floor, objecting to spending measures and projects that he considered wasteful, prompted Time magazine to label him "the useful pest.

[2] After the war, he briefly attended Iowa State College in its electrical engineering program, before transferring to the University of Missouri School of Journalism in Columbia.

[2] In 1940, Gross challenged Iowa's sitting Governor, George A. Wilson, in the Republican primary, running what newspapers called a "sight-unseen" campaign.

Gross confined his campaign to radio addresses, declined all personal appearance invitations, and made no platform speeches.

[5] His campaign was haunted by a statement he had made seven years earlier, while writing and speaking for the Farmers' Holiday Association, that appeared to approve of an episode of mob violence against a judge to stop a foreclosure.

[1] He denounced, among other things, the Marshall Plan,[7] the funeral of President John F. Kennedy (including the appropriation for fuel for the eternal flame),[2][7] the size of the White House security detail,[7] the Peace Corps,[7] the U.S. Space Program,[7] and foreign aid.

As Ed Rollins recalled, "When he retired, his fellow members chipped in and bought him and his wife Hazel, who managed his office for no pay, a round-the-world trip.

He opposed restoring former President Dwight D. Eisenhower to his generalship unless Congress stipulated that he would only receive his Presidential pension and not a general's salary also.

[1][2] Gross admitted to having only one regret about his entire career: voting "present" rather than "nay" on the Gulf of Tonkin Resolution, explaining that the Vietnam War ended up costing too much.

[2][23] He was a resident of Arlington, Virginia, until his death in a Washington, D.C. Veterans Hospital on September 22, 1987, due to complications from Alzheimer's disease.