Jesse Alexander Helms, Jr. (October 18, 1921 – July 4, 2008) was a five-term Republican United States Senator from North Carolina who served as chairman of the Senate Foreign Relations Committee from 1995 to 2001. A leading conservative, he helped organize and fund the conservative resurgence in the 1970s, aiding Ronald Reagan's quest for the White House and helping many local and regional candidates.

A journalist by training, Helms was the longest-serving popularly elected Senator in North Carolina's history, and was widely credited with shifting the one-party state dominated by the Democrats into a competitive two-party state. The Helms-controlled National Congressional Club's state-of-the-art direct mail operation raised millions for Helms and other conservative candidates allowing Helms to outspend his opponents in most of his campaigns.

An unreconstructed Southern conservative, he began his political career in the Democratic Party in the days when many white Southern politicians championed racial segregation. He moved to the Republican party in the 1970s. Helms was the most stridently conservative politician of the post-1960s era, especially in opposition to federal intervention into what he considered state affairs (integration, the Civil Rights Act and the Voting Rights Act). Helms tried, with a 16-day filibuster, to stop the Senate from approving a federal holiday to honor Martin Luther King, Jr.

Helms was credited even by his most vociferous opponents with providing excellent constituent services through his Senate office.

As long-time chairman of the powerful Senate Foreign Relations Committee, he demanded a staunchly anti-communist foreign policy that would reward America's friends abroad, and punish its enemies. His relations with the State Department were often acrimonious, and he blocked numerous presidential appointees. However, he worked smoothly with Secretary of State Madeleine Albright.

In domestic affairs, Helms promoted industrial development in the South, seeking low taxes and few labor unions so as to attract northern and international corporations to relocate to North Carolina.

On social issues, Helms was a traditionalist. He was a "master obstructionist" who relished his nickname, "Senator No". He opposed, at various times, civil rights, disability rights, feminism, gay rights, affirmative action, abortion, and government support for contemporary art with graphic sexuality. Helms brought an "aggressiveness" to his conservatism, as in his rhetoric against homosexuality, and employed racially charged language in his campaigns and editorials. He combined cultural, social and economic conservatism which often helped his legislation win overwhelming support. The Almanac of American Politics once wrote that "no American politician is more controversial, beloved in some quarters and hated in others, than Jesse Helms".