We Are

We are leaner, more responsive, more aggressive, and more attentive.


Uniquely Chicago

We are uniquely Chicago and our Chicago heritage is reflected in our tenacious legal style.


For Business Clients

We started this firm with the idea that helping people do business shouldn’t cost them a fortune: find out what they need and help them get it.


Our skills were refined in the forges of Cook County's Criminal Courts where, as prosecutors, all three partners tried cases daily.

We have not spent our legal careers sitting in offices, shuffling papers.

We have tried hundreds of cases, including numerous jury trials.

While taking a case to trial is a matter of last resort and should be approached cautiously, there are times that it cannot be avoided.

When that time comes, we will pursue your matter aggressively to get you a quick resolution.


We are the rare blend of attorneys with aggressive trial skills and business sense.

O'Mara, Gleason, & O'Callaghan, LLC is an alternative to everything you know and do not like about lawyers and law firms. We are not the law firms you know. We are not the lawyers who have frustrated you in the past. Our smaller size makes us responsive and cost efficient. Our trial experience makes us aggressive.

Our business experience has made us more attentive to the needs of businesses, whether you are a start-up entrepreneur or an established corporation. We are your alternative. We will listen. We will involve you in the strategy of your case.

We will not nickel and dime you for our services.


The aggressive yet collegial nature of our firm is a direct result of the characters of our partners.

Like a compass, we represent the three points of the city. Peter O'Mara was born and raised on the western edge of Chicago in Oak Park. Richard Gleason is from north of the city in Evanston. And, Sean O'Callaghan grew up on the south side of Chicago in the Beverly and Mt.Greenwood neighborhoods.

Our friends and family are a cross-section of this city. They are union men and women. They are small and mid-sized business owners. They are plumbers, contractors, doctors, bankers, and brokers.

It is with their needs in mind that we started this firm.


We started this firm with the idea that helping people do business shouldn’t cost them a fortune: find out what they need and help them get it.

We began working with companies in late 2006 and much of our work has been done in an era of economic recession. Our first clients were friends and family who were small and mid-sized business owners. We learned from them that they felt compelled to hire large law firms because they perceived that large firms had better knowledge and experience. However, these same business owners became frustrated by their large law firms’ unwillingness to get aggressive and litigate — not to mention the fees they charged.

We realized that there was a niche in this market for small and mid-sized businesses that need lawyers with our trial experience and business knowledge. Most business law firms have no experience trying cases and therefore are reluctant to push cases to litigation. These firms are content taking court date after court date or dragging matters out for months or years in order to avoid trials. For you, the client, that means that you continue to pay month after month of legal bills and your matter gets no closer to resolution.

This is not how we serve our business clients. As trial attorneys, we draft all of our documents with an eye towards potential litigation. And, while we know that avoiding trial is frequently the best business decision, we’re not afraid to take a case into the courtroom, because we know how to win once we’re there.

What is certain in the area of business law is that irrespective of how much time is spent drafting an agreement, the potential for future disputes cannot be entirely eliminated. You will benefit from the combination of our trial experience and practical understanding of business.


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