Ambassador to Ireland and nominee for governor in 2010 Thomas C. Foley and Groton Town Councilor Heather Somers, making the contest a rematch of the 2010 election.

Former State Representative Jonathan Pelto (D-Mansfield) [1] explored a third-party candidacy through a petition drive but was disqualified due to an inadequate number of signatures.

[5] Danbury Mayor Mark Boughton and State Senate Minority Leader John McKinney took 22.3% and 17.72%, respectively, meeting the 15% vote threshold and thus also qualified for the primary ballot.

[6] Shelton Mayor Mark Lauretti and former West Hartford Town Councilor Joe Visconti failed to get 15% of the vote at the convention, so neither automatically qualified for the ballot.

[8] On June 6, Visconti announced that he was short of the required number of signatures, and with the filing deadline only 4 days away, was withdrawing from the race to run as an Independent instead.

Heather Bond Somers had originally been running on such a "ticket" with Mark Boughton,[30] but she withdrew from the arrangement.