Former representative James Stanton of Ohio announced his candidacy yesterday for chairman of the Democratic National Committee, becoming the fifth contender for the job being vacated by Paul G. Kirk Jr.

Stanton said he recognizes that he is not the front-runner and said Michigan Democratic Chairman Richard Wiener is "obviously the insider" in the race. He said he expects to compete with Washington lawyer Ronald H. Brown for organized labor's support. The other candidates are former representatives James R. Jones of Oklahoma and Michael D. Barnes of Maryland.

Sen. Dale Bumpers (Ark.), mentioned as a possible contender, announced yesterday that he will not be a candidate.

Stanton said he could unite the party "because I am not the candidate of the South or the candidate of the Northeast or the candidate of the right or the left. I am simply the candidate of the Democratic Party, the whole party."

Stanton, a former House member and Cleveland City Council president who went into business after a 1976 Democratic primary loss to Sen. Howard M. Metzenbaum, maintained that his background qualifies him for the job.

"I've built a ward organization, I've run a city council, I've run an $800 million business," he said. "I have the communications skills to talk to the people who are going to financially energize any political party in this country."

The party chairman is to be chosen at a meeting here Feb. 9-10.