Russ Feingold Democratic Ron Johnson Republican The 2010 United States Senate election in Wisconsin was held on November 2, 2010.

Incumbent Democratic Senator Russ Feingold lost re-election to a fourth term to Republican challenger Ron Johnson, a businessman and first-time candidate.

[2] On the ballot Declined Former Republican Governor of Wisconsin Tommy Thompson had expressed an interest in challenging Feingold,[7] but ruled himself out of the race in April 2010.

In response to controversy over his ownership of stock in BP, Johnson said he would sell it when market conditions were favorable and possibly use the proceeds to help finance his Senate campaign.

In July 2010, Feingold's second 2010 television election ad attacked Johnson for alleged support for offshore drilling in the Great Lakes.