Serving Beloit and surrounding areas

Contact John G Onderak, DDS - Beloit, WI | 608-363-9400

John G Onderak is a native of Beloit. He was born and raised here. His connection to the community is a lasting one. This is why he aims at giving his best to the people of Beloit.

You can depend on him for professional, gentle and friendly service.

Call us anytime for an appointment. We are happy to accept all patients. Don't

hesitate to come to our clinic.


  • Our Lady Of The Assumption Catholic Grade School

  • Beloit Catholic High School

  • BA in Biology from Loras College

  • DDS from Marquette University


Dr. Onderak is a member of:

  • Rock County Dental Society

  • Wisconsin Dental Association

  • American Dental Association

Active memberships

He has been a practicing dentist for over 31 years now. In this time he has had many happy customers ranging from kids to adults.

Experienced work

Meet The Person Who'll Put the Smile Back on Your Face!

Teeth Dental service