The most predominant denominations among residents in Barry County who adhere to a religion are Southern Baptists (50.27%), Roman Catholics (19.26%), and United Methodists (4.67%).

Barry County, along with the rest of the state of Missouri, is represented in the U.S. Senate by Josh Hawley (R-Columbia) and Eric Schmitt (R-Glendale).

Like most rural areas throughout Missouri, voters in Barry County generally adhere to socially and culturally conservative principles which tend to influence their Republican leanings.

On the Democratic side, former Vice President Joe Biden (D-Delaware) both won statewide and carried Barry County by a wide margin.

Incumbent President Donald Trump (R-Florida) faced a primary challenge from former Massachusetts Governor Bill Weld, but won both Barry County and statewide by overwhelming margins.

Businessman Donald Trump (R-New York) narrowly won the state overall, but Senator Ted Cruz (R-Texas) carried a plurality of the vote in Barry County.

On the Democratic side, former Secretary of State Hillary Clinton (D-New York) both won statewide and carried Barry County by a small margin.

Senator Rick Santorum (R-Pennsylvania), who finished first in the state at large, but eventually lost the nomination to former Governor Mitt Romney (R-Massachusetts).

In 2008, the Missouri Republican Presidential Primary was closely contested, with Senator John McCain (R-Arizona) prevailing and eventually winning the nomination.

Despite initial reports that Clinton had won Missouri, Barack Obama (D-Illinois), also a Senator at the time, narrowly defeated her statewide and later became that year's Democratic nominee, going on to win the presidency.