License & bar number lookup
Illinois Attorney License Lookup
Search 206,900 attorneys registered with the Illinois Attorney Registration & Disciplinary Commission (ARDC) by name or bar number. Every record shows the official license status and as-of date.
How to verify a Illinois attorney
- Search the attorney by name or bar number in the search box above — it pulls the official Illinois Attorney Registration & Disciplinary Commission (ARDC) record.
- Confirm the license status reads "active" (not suspended, disbarred, inactive, or not eligible).
- Check the disciplinary standing — disbarred or suspended is a public record you can see before you hire.
- Cross-check the bar number and admission year against anything the attorney told you.
Illinois attorneys — last name “O”
Active Illinois attorneys with last names starting “O.” Use the search box above for an exact name or bar number.
Donald Allyn O'Brien
Geneva, IL
- Bar #
- 0966728a-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1977 · 49 yrs
Dennis Sean O'Brien
Chicago, IL
- Bar #
- 2ce9574d-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1978 · 48 yrs
James Vincent O'Brien
Brentwood, MO
- Bar #
- b73da1bc-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1980 · 46 yrs
Jay Timothy O'Brien
Mokena, IL
- Bar #
- 6ecc8e5f-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1981 · 45 yrs
Darren William O'Brien
Orland Park, IL
- Bar #
- b9d54ac6-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 1983 · 43 yrs
James Patrick O'Brien
Chicago, IL
- Bar #
- e95322b5-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1983 · 43 yrs
Norah A. O'Brian
West Bloomfield, MI
- Bar #
- bb729859-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1985 · 41 yrs
Daniel Edward O'Brien
Geneva, IL
- Bar #
- 29873aa3-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1989 · 37 yrs
Gerard James O'Brien
Palatine, IL
- Bar #
- 21fa2497-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1989 · 37 yrs
Anne Maureen O'Brien
Chicago, IL
- Bar #
- 866f19c7-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1991 · 35 yrs
Daniel W. L. O'Brien
Carlinville, IL
- Bar #
- d687029c-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 1991 · 35 yrs
Candace Marie O'Brien
Miami, FL
- Bar #
- 229adb21-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 1992 · 34 yrs
Daniel Emmett O'Brien
Chicago, IL
- Bar #
- 7d2e399d-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1992 · 34 yrs
Dana Keone O'Banion
Rosemont, IL
- Bar #
- c1fc10cd-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1993 · 33 yrs
Brien Joseph O'Brien
IL attorney
- Bar #
- fe14b927-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1993 · 33 yrs
Andrew A. O'Brien
Saint Louis, MO
- Bar #
- 694521c1-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1995 · 31 yrs
Brendan Alan O'Brien
IL attorney
- Bar #
- 12981c91-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1996 · 30 yrs
Charles Thomas II O'Brien
Stamford, CT
- Bar #
- 0d8852f1-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 1997 · 29 yrs
Cheryl L. O'Brien
Winnetka, IL
- Bar #
- 5a9f520f-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1997 · 29 yrs
Dana N. O'Brien
Chicago, IL
- Bar #
- 95f92497-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 1998 · 28 yrs
Daniel Mark O'Brien
Wilmette, IL
- Bar #
- 82385d15-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1998 · 28 yrs
Donal Maurice O'Brien
Chicago, IL
- Bar #
- 419f520f-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 1998 · 28 yrs
Anthony Michael O'Brien
Chicago, IL
- Bar #
- 182adbd8-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2000 · 26 yrs
Erin Elizabeth O'Brien
Chicago, IL
- Bar #
- 6b0aa371-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2000 · 26 yrs
Barton James O'Brien
Chicago, IL
- Bar #
- 191a9765-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2002 · 24 yrs
Andrew Patrick O'Brien
Chicago, IL
- Bar #
- 48ea9a09-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2003 · 23 yrs
Bridget Kathleen O'Brien
Markham, IL
- Bar #
- de1b9765-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2004 · 22 yrs
Colin Thomas Jefferson O'Brien
Chicago, IL
- Bar #
- d3400de5-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2004 · 22 yrs
Daniel Joseph O'Brien
Springfield, IL
- Bar #
- 0da47a03-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2004 · 22 yrs
Erin Webster O'Brien
Joliet, IL
- Bar #
- 9d592fc0-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2004 · 22 yrs
Alexander Scott O'Brien
Kankakee, IL
- Bar #
- 0b7019c7-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 2006 · 20 yrs
Elizabeth Ann O'Brien
Atlanta, GA
- Bar #
- 8ca515df-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2006 · 20 yrs
Elizabeth Colsant O'Brien
Chicago, IL
- Bar #
- 8b6843ae-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2006 · 20 yrs
Eleanor Kennedy O'Brien
Chicago, IL
- Bar #
- 77a57a03-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2008 · 18 yrs
Shannon Frances O'Boye
Northbrook, IL
- Bar #
- b58552f1-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2009 · 17 yrs
Erin Lucille O'Boyle
Springfield, IL
- Bar #
- 2d5222b5-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 2009 · 17 yrs
Daniel Mark O'Brien
Chicago, IL
- Bar #
- b80d00c9-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2009 · 17 yrs
Conor Logan O'Brien
Denver, CO
- Bar #
- 5d1832a9-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 2010 · 16 yrs
Erin Elizabeth O'Brien
Chicago, IL
- Bar #
- 650e00c9-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2011 · 15 yrs
Claire Kaltenbach O'Brien
St. Louis, MO
- Bar #
- cc024ffd-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2013 · 13 yrs
Emily O'Brien
Chicago, IL
- Bar #
- 55df248b-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 2013 · 13 yrs
Susan E. O'Banion
Riverwoods, IL
- Bar #
- 68f4f37d-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2014 · 12 yrs
Jason Charles O'Brien
Fpo
- Bar #
- 5dcf5aeb-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2014 · 12 yrs
Jennifer Lynn O'Brien
Alexandria, VA
- Bar #
- 2b0d5df7-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 2014 · 12 yrs
Casey Kathleen O'Brien
Minneapolis, MN
- Bar #
- 20981c91-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 2017 · 9 yrs
Daniel Richard O'Brien
St. Louis, MO
- Bar #
- 9ba5920f-aa64-eb11-b810-000d3a9f4eeb
- Admitted
- 2017 · 9 yrs
Jeffrey Michael O'Brien
Quncy, IL
- Bar #
- 1a2e399d-a964-eb11-b810-000d3a9f4eeb
- Admitted
- 2018 · 8 yrs
Donncha O Tuama
Dallas, TX
- Bar #
- 86264a09-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2019 · 7 yrs
Sean Patrick O Sullivan
Lebanon, TN
- Bar #
- 7060683a-ab64-eb11-b810-000d3a9f4eeb
- Admitted
- 2020 · 6 yrs
David Joseph O Connor
Chicago, IL
- Bar #
- d42c2fd1-7848-ec11-b842-000d3a90a8fc
- Admitted
- 2021 · 5 yrs
Kaitlyn Marie O'Boye
Chicago, IL
- Bar #
- 5ee920ab-71b2-eb11-b81e-000d3a9f4eeb
- Admitted
- 2021 · 5 yrs
Ashlyn Christine O'Brien
Morrisville, NC
- Bar #
- d0024aeb-71b2-eb11-b81e-000d3a9f4eeb
- Admitted
- 2021 · 5 yrs
Camille O'Brien
Chicago, IL
- Bar #
- 705cb3d9-70de-eb11-b82f-000d3a907e09
- Admitted
- 2021 · 5 yrs
Emily A. O'Brien
Lansing, MI
- Bar #
- 09302fd1-7848-ec11-b842-000d3a90a8fc
- Admitted
- 2021 · 5 yrs
James Patrick O'Brien
Chicago, IL
- Bar #
- 77302fd1-7848-ec11-b842-000d3a90a8fc
- Admitted
- 2021 · 5 yrs
Jeffrey O'Boyle
Wheaton, IL
- Bar #
- 7aac629b-eb6c-ed11-b85c-000d3a90a8fc
- Admitted
- 2022 · 4 yrs
Seamus O Connor
Arlington Heights, IL
- Bar #
- 5646c806-ffbe-f011-b8ac-000d3a92ce24
- Admitted
- 2025 · 1 yr
Matthew James O'Boyle
Chicago, IL
- Bar #
- e849c806-ffbe-f011-b8ac-000d3a92ce24
- Admitted
- 2025 · 1 yr
Catherine Rose Clinton O'Brien
Chicago, IL
- Bar #
- e047c806-ffbe-f011-b8ac-000d3a92ce24
- Admitted
- 2025 · 1 yr
Robert Ames O'Boyle
Chicago, IL
- Bar #
- f5a99801-ef55-f111-b8c7-000d3a92ce24
- Admitted
- 2026 · 0 yrs
Disciplinary actions
See Illinois attorney disciplinary actions (2,992 attorneys currently disbarred or suspended of record).
Frequently asked questions
How do I check if a lawyer is licensed in Illinois?
Search their name or bar number in the lookup above. It returns the official Illinois Attorney Registration & Disciplinary Commission (ARDC) record, including current license status and admission year. If no record comes back, the person may not be licensed in Illinois.
How many attorneys are registered in Illinois?
206,900 attorneys are registered with the Illinois Attorney Registration & Disciplinary Commission (ARDC), and 84,758 are on active status. Every record here shows the official license status and as-of date.
Is Illinois attorney discipline public?
Yes. License status, including disbarment and suspension of record, is public information published by the Illinois Attorney Registration & Disciplinary Commission (ARDC). 2,992 Illinois attorneys are currently disbarred or suspended of record.
What is a bar number?
A bar number is the unique ID the Illinois Attorney Registration & Disciplinary Commission (ARDC) assigns to each admitted attorney. It is the most reliable way to confirm you are looking at the right person, especially for common names.
Does this cost anything?
No. Looking up a Illinois attorney's license and disciplinary standing on this site is free and requires no account.
Data sources & last updated
- Licensing roster & status: Illinois Attorney Registration & Disciplinary Commission (ARDC). Published active-attorney total (2025 Annual Report).
- Resident-attorney benchmark: ABA National Lawyer Population Survey 2024.
- Data on this page as of 2026-06-13 (last roster ingest).
This site republishes official public records and is not legal advice, a lawyer referral service, or a consumer reporting agency. Information here may not be used to make decisions about employment, tenancy, or credit (FCRA). Records are shown as published by their official sources and may contain errors or be out of date; consult the linked official source to verify. To correct or dispute a record, contact the licensing authority of record.