When Father William O’Mara turned 90 years old Feb. 7, he had a school full of students and coworkers to celebrate with him.

O’Mara, who was ordained for the Archdiocese of Chicago in 1958, has served as chaplain at Marian Catholic High School in Chicago Heights for the past 13 years, celebrating school Masses, attending about a half dozen Kairos retreats with seniors each year and going to sports events, concerts and plays.

“He does more in retirement than most people do who are working full-time,” said Marian Catholic Principal Steve Tortorello. “He makes the effort to be present in the kids’ lives. He’s not just the priest who says Mass, although of course he does that. He’s a member of the community who knows the kids and he’s here for the staff too.”

So it only made sense to make a big deal of his birthday. He was honored on the video board  in the gym during school Mass, and he was made an honorary assistant coach for the Feb. 16 varsity boys’ basketball game against DePaul Prep, a 40-39 victory for Marian Catholic.

That meant O’Mara wasn’t sitting in his usual spot, at the top of the bleachers behind the Marian Catholic bench. The school marked the spot with a banner anyway. Before the game, O’Mara was presented with a game ball and a book of birthday greetings.

“I knew I was going to sit at the end of the bench here,” O’Mara said. “But I didn’t know they were going to make such a big deal out of it.”

During halftime, O’Mara shrugged at the idea that he was doing a lot for the school.

“Otherwise, I’d be sitting home knitting,” the Mokena resident said, then clarified that he doesn’t actually knit. “Really, I’ve been involved in high school education for a long time.”

O’Mara, who was assigned after ordination to Infant Jesus of Prague Parish in Flossmoor, was the first priest to celebrate Mass at Marian Catholic when it was founded, Tortorello said.

“He was there at the beginning,” he said.

He also has been a frequent celebrant of weekend Masses at parishes in the area, Tortorello said, so Chicago Heights issued a proclamation for his birthday,

O’Mara was on the faculty of Quigley South, teaching and coaching several sports and serving as athletic director, according to Gerry O’Brien, one of O’Mara’s students at Quigley South. O’Brien now is a college counselor at Marian Catholic.

After college, O’Brien said, O’Mara offered him a job teaching high school theology at a high school in Tyler, Texas, where O’Mara was principal. O’Brien didn’t want to move to Texas, but he ended up working with his former teacher years later at Marian Catholic.

“It doesn’t matter how old you are,” O’Brien said. “The kids understand him. They get him. He doesn’t come across as preachy. He does come to a lot of activities. If there’s an activity that Marian students are involved in, you can bet you’re going to find him there.”

Theology teacher Gary Kopycinski said O’Mara is “one of the most pastoral people I’ve ever met. He’s a wonderful priest.”

That’s because O’Mara speaks person-to-person and heart-to-heart instead of speaking only about ideas, he said.

“He has a really good feel for people,” he said.

While it might be surprising to see teenagers respond so well to someone more than 70 years their senior, they can tell he’s genuine.

“And they can tell in a minute when someone is not being real,” he added.

After decades working with teenagers, O’Mara said some things have changed.

“Obviously, the world’s changed,” he said. “I think the world is tougher today because of technology. They know so much, and you can’t avoid it, so they have a lot of struggles.”

But, he said, the students at Marian Catholic want to help and contribute to the world.

“They’re much more involved in service that we ever were growing up,” he said. “They might be less religious in terms of going to church, but they are very service oriented.”