The vacancy is created by Judge Susan Dlott who took senior status at the end of May, meaning she'll oversee fewer cases.
Senators Sherrod Brown (D-OH) and Rob Portman (R-OH) are creating a bipartisan judicial advisory committee to review applications and make recommendations.
"I am confident that the bipartisan commission will evaluate applications thoughtfully to help us recommend the best people possible to the president," says Portman in a joint statement.
Brown adds, "I know the commission is devoted to finding the best possible candidates to continue her important work."
President Donald Trump is responsible for making the final recommendation. It must then be confirmed by the Senate.
U.S. district courts hear criminal and civil cases. The Southern District of Ohio serves more than 5 million Ohioans, according to its website.
Dlott was appointed to the court in 1995 by President Bill Clinton. She served as chief judge from 2009 - 2014.