Julia Letlow, the wife of Representative-elect Luke Letlow, a Louisiana Republican who died of complications from Covid-19 days before he was to be sworn in, will seek the open seat in an upcoming special election.

Ms. Letlow will run as a Republican to represent Louisiana’s Fifth District, which covers the conservative northeastern part of the state. Her husband died on Dec. 29 at the age of 41 after suffering from a “cardiac condition” while hospitalized with the virus. His death came just weeks after he won the seat vacated by his former boss, Representative Ralph Abraham.

“Everything in my life and in my marriage has prepared me for this moment,” Ms. Letlow wrote in a statement on Thursday. “My motivation is the passion Luke and I both shared: to better this region that we called home and to leave it a better place for our children and future generations.”

Mr. Letlow, a longtime Republican aide, backed social distancing measures and the wearing of masks during his campaign, though photos from his social media accounts also showed him campaigning indoors without masks at times. He also argued for the loosening of some coronavirus restrictions when infections ebbed over the summer.

Ms. Letlow, who lives in Richland Parish, currently serves as the director of external relations and strategic communications at the University of Louisiana in Monroe.

Her entrance into the nonpartisan election on March 20 was widely anticipated and may discourage other Republicans who had been mulling a run from entering the race.

She is likely to face Allen Guillory Sr., a Republican from Opelousas, who tallied under 10 percent in the Nov. 3 election, and Sandra “Candy” Christophe, a Democrat from Alexandria who announced last week she would run.

Ms. Letlow has been active in Louisiana Republican politics for years and was selected for her university job, in part, to provide “insight into strategies and alliances” that would be helpful for the school during its interactions with elected officials, her online biography said.

“I am running to continue the mission Luke started — to stand up for our Christian values, to fight for our rural agricultural communities and to deliver real results to move our state forward,” she said in her statement.