Ocean County Democrats announced their support for Buono during a party meeting Saturday in Toms River.
Buono has also been endorsed by the Democratic Party organizations in Somerset and Monmouth counties, while top Democrats in Middlesex County have pledged their support ahead of their upcoming party meeting. She also has the support of Sussex County Democratic Chairman Mike Busche.
Buono, who lives in Metuchen, is the only Democrat in the race so far. If she wins her party's nomination, she would face incumbent Republican Chris Christie in November.
Early polls show that any Democrat is likely to struggle against Christie, who has received widespread praise for his leadership during and after Superstorm Sandy.