Mark Allen Callahan (born May 11, 1977) is an American information technology consultant and perennial candidate.

[3] Later in 2010, Callahan ran for the Oregon House of Representatives, unsuccessfully seeking the nomination of the Independent Party of Oregon before receiving the nomination of the Pacific Green Party, in what he later said was an attempt to take away votes from the Democratic incumbent, Nancy Nathanson, in order to help the Republican nominee win.

[1] Later in 2012, Callahan won the Republican nomination without opposition for the same Oregon House of Representatives seat he had sought in 2010, losing again to Nancy Nathanson in the general election.

[8] In 2014, Callahan sought the Republican nomination for the U.S. Senate, receiving nearly 7% of the vote and coming in third place, behind Jason Conger and eventual nominee Monica Wehby.

[9][10] During this campaign, Callahan was featured on Fox News after an argument with Nigel Jaquiss, a reporter, resulted in him being kicked out of a Willamette Week editorial interview.

[12][13] He won the primary over businessman Sam Carpenter, Lane County Commissioner Faye Stewart, and business consultant Dan Laschober.

[18] He won the Republican nomination in May 2018, but was defeated by Democrat Kurt Schrader in the November general election.

[22] In January 2017, The Register Guard reported that Callahan received Supplemental Nutrition Assistance Program (SNAP) benefits - also known as "food stamps" - shortly after funding his 2014 U.S. Senate campaign.

Callahan further claimed that he was laid off from his network administrator job on March 21, 2014, because his employer needed a full-time person.