Skip to main content

Cosmas M. Onyia

Divorce and separation Attorney at Phoenix, AZ

5.0   3 reviews
  • State Years
    Arizona - AZ 29 years
    Washington - WA 30 years
  • Licensed for 29 years
    State AZ
    Acquired 1994
    Active No misconduct found
  • Licensed for 30 years
    State WA
    Acquired 1993
    Active No misconduct found

We have not found any instances of professional misconduct for this lawyer.

About Cosmas

Learn Cosmas’s areas of practice.


Cosmas M. Onyia
3636 N Central Ave Ste 800
Phoenix, AZ, 85012-1938

Similar lawyers nearby


5.0 / 5.0
  3 customer reviews
5 Star
4 Star
3 Star
2 Star
1 Star
Posted by Archie | January 18, 2022
This review is from a person who hired this attorney.
| Hired Attorney
Cosmas Onyia
Thank you so much Mr Onyia for getting me through another crisis and making it look so easy. Your logical and calm demeanor had kept me at ease during this anxious time concerning the custody of my son. Your a heaven sent, like having Einstein, Mohammed Ali and Mike Tyson in my corner at the same time. If your looking for representation in family courts, this is your man. He knows his way around the courtroom. Mr Onyias experience shined throughout my case that went to trial. Mr Onyia was in control the whole time. He knows the law and how to navigate through difficult opposition and circumstances. I've shopped around for family court attorneys in 2019, they all seemed unreasonable and extravagant with their court fee estimates. Mr Onyia was the only one who seemed honest, fair and reasonable. He was worth every penny and more in 2019. He never inflated extra costs or expenses like most lawyers. Now I've just finished up with my uphill custody modification battle in 2022. We won.
Read less
Posted by Ryan | January 27, 2018
This review is from a person who hired this attorney.
| Hired Attorney
Outstanding representation
Cosmas Onyia recently represented us in a custody matter. Throughout the process, Cosmas was detailed in his explanation of what to expect. He guided us thru the process and was very timely with responses to any questions we had. He would either answer immediately or within 24 hours. Given that he was brought into the case late after poor representation by another council, Cosmas picked up the pieces in short notice and put forth a vigorous case on our behalf. As one might imagine, these type of cases are often quite emotional at times. Ours was no different. When things got upsetting, Cosmas helped to keep us focused and see the bigger picture. Cosmas was very aggressive on our behalf and set forth a determined argument that was presented in an organized expert manner. The opposing council was so out matched by Cosmas that at times we almost felt sorry for the other side. If you have any need for a family lawyer, you would be foolish not to entrust Cosmas to be your council.
Read less
Posted by Leticia | May 29, 2015
Divorce case
He was excellent with my case, I cant be more thankful for his excellent service.


  • Free Consultation 30 minutes
Payment methods
Cash, Check, Credit Card


AVVO RATING 6.5 (Good)

Work Experience

  • Attorney
  • 1994 - Present


  • University Of Idaho Law School
  • JD - Juris Doctor
  • 1991

Languages Spoken

  • English

Attorney endorsements

Received (0)
Given (0)
Endorse Cosmas
Endorsements from fellow lawyers are an important consideration for many when selecting the right attorney.
This attorney hasn't created any attorney endorsements recently on Avvo.

Avvo Contributions

This attorney hasn't created any legal answers in Q&A or legal guides recently on Avvo.

No Photo
Cosmas M. Onyia
Divorce and separation Attorney
Phoenix, AZ
Licensed for 30 years
Free Consultation