William Michael (Mike) O’Fallon

Macken Funeral Home Memorial Photo
Date of Birth:
Wednesday, March 7, 1934
Date of Death:
Saturday, February 19, 2022
87 years old

Memorial Service

Date: Saturday July 30, 2022
Time: 11:00 am

Location: River Park Chapel at Macken Funeral Home [ view map ]

Macken Funeral Home Memorial Photo
Date of Birth:
Wednesday, March 7, 1934
Date of Death:
Saturday, February 19, 2022
87 years old
Macken Funeral Home Memorial Photo
Date of Birth:
Wednesday, March 7, 1934
Date of Death:
Saturday, February 19, 2022
87 years old

William Michael (Mike) O’Fallon

William Michael (Mike) O’Fallon was born to John and Luella Smith O’Fallon in Princeton, MN, on March 7, 1934. Although the doctor told his parents to “Take him home and keep him warm until he dies,” he fortunately survived. He died on February 19, 2022, in his home in Charter House in Rochester MN.

Mike graduated from Litchfield MN High School in 1952 and St. John’s University (SJU) in Collegeville MN in 1956. Expecting to become a high school teacher, he attended Vanderbilt University, where he earned a Master of Arts degree with a major in mathematics in 1957. He was then recruited to teach mathematics at SJU in fall 1957.

When asked to teach Statistics at SJU, he took summer courses in statistics at the University of Wisconsin Madison in 1958 and Oklahoma State in 1959, where he was encouraged by his statistics teachers to return to graduate school to obtain a doctorate in statistics. In 1960 he was accepted into the doctoral program at the Mathematical Statistics Department of the University of North Carolina at Chapel Hill (UNC-CH), where he met his future wife! He completed his PhD in Mathematical Statistics in 1967.

In 1965, he was recruited by Duke University into a biostatistics position jointly funded by Duke’s Medical School and Department of Mathematics. After promotion to the tenured position of Associate Professor, he decided to use his sabbatical year to study Epidemiology. In 1974 Mayo Clinic’s Department of Statistics and Epidemiology accepted him to design a breast cancer epidemiology study.

In September 1974, Mayo recruited him to chair the Biostatistics Section, a position he held for the next 20 years. During these years the Section more than doubled in personnel and productivity and established a successful promotion system for the staff. He was promoted to Professor in the Mayo Medical School, co-authored more than 450 peer-reviewed publications, served as Principal Investigator or co-investigator on nearly 50 major grants, and served on several NIH & FDA committees. In 1994 he was appointed to chair Mayo’s Department of Health Sciences Research, a position he held until the year 2000. He continued his statistical consulting activities for several years after he retired from Mayo in 2002.

He was a member of several professional organizations, notably the American Statistical Association (ASA Fellow 1986) and the American Association for the Advancement of Science (AAAS Fellow 1994). He was especially active in the ASA, ultimately being elected to serve as ASA President in 2000 and given the ASA Founder’s Award in 2002 “for extraordinarily effective leadership.”

At his first class at UNC-CH (1960), he discovered that one of his classmates (Judith Rich) was a fellow Minnesotan. He kindly offered to be her study partner. Quickly the friendship turned into something more, and they were married a year later on September 2, 1961, at St. John Vianney Catholic Church in Fairmont, MN. They continued their statistics studies and professional development together until death parted them 60 years later.

Family was important to Mike. He enjoyed spending time with his sons Sean and Liam. He actively supported their sporting, musical, and academic interests. When they got married, he took pleasure in visiting their families and getting to see his grandkids.

Mike had a wide range of interests and loved to share them. He was a hunter, golfer, long-distance runner, bowler, wrestler, and softball player and became an accomplished soccer referee. He liked to play cards and loved to read and hang out in bookstores and libraries. His personal passion was genealogy–he spent lots of time and effort to learn about the O’Fallon and Rich families, where they came from, and what they did. He was never happier than when he could share his knowledge with relatives and friends.

Mike was committed to making the world a better place. In the 1960s he championed civil rights and voting rights. In retirement he served as the interim director of the Channel One Food Bank. He was active in The Rotary Club of Rochester, serving as Club President in 2005 and Assistant District Governor in 2009-2011. He was active in his church, too, serving on committees, participating in men’s group activities, mentoring new members, and lectoring.

Mike is survived by his wife Judy, sons Sean (Maureen Popp) and Liam (Janine Barden), grandchildren Emily (Sean & Maureen), Lydia, Cade, and Ian (Liam & Janine), his brothers John and David, and many beloved nieces and nephews.

We wish to express our deepest appreciation for the caregivers at Charter House for their kindness and support for Mike in his final months.

A memorial service to celebrate his life will be held in Rochester this summer, when family members and friends can attend. In lieu of flowers, donations in Mike’s name can be made to the Channel One Food Bank (https://www.helpingfeedpeople.org/) or your favorite charitable organization.

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The family of William Michael (Mike) O’Fallon has received the following condolences.

I was very sorry to hear about Mike.  I took his introductory statistics class at Duke my junior year ('70-'71) and enjoyed it immensely.  I guess I made an impression on Mike because when he established a masters degree in statistics and computing at the end of my senior year, he recruited me into it as the program's first student, and gave me a 1/2 time job as a programmer that made it financially possible for me to get the degree.  That set me on a rewarding career path as a statistical programmer at Duke from which I retired in 2018.   He had a huge impact on the direction of my career and life, for which I have always been grateful.    He was a special person and wonderful teacher and I know he is missed.

Judy Stafford

We are deeply sorry to hear of Mike’s passing. He led a very Christ centered life and is an inspiration. We really enjoyed his sense of humor and kindness. We are so glad we knew him and spent time with him.

Dear Judy,

We are so sorry to read about Mike’s passing.  Being on a Marriage Encounter team with you both many years ago was a joy.  Mike was a great, humble  and loving guy.  We remember his tight hugs and words of encouragement.  Our thoughts and prayers are with you as you mourn the death of your dear Mike.

Sending our deepest sympathy and lots of love,  Ken and Sandy Wagner



We were so sorry to hear about Mike.  The obituary that appeared in the paper was a good one.  He was department head when I came to Mayo, and he seemed to get a lot of pleasure from teaching me how to do the job, both by introducing me to whole areas of statistics and by helping me learn how to go about consulting.  I'll always be grateful to him.

We've seen both you and him infrequently the past few years, but we'll always remember you both.  


   Peter and Gail Wollan

My sympathy to you Judy and all of the members of your family.  Mike and I graduated together at St. Johns University (SJU) in 1956.  He was part of a sizeable group that came from Litchfield, Minnesota in 1952.  A great classmate and an exceptional human being.  Mike was a part of our Tuesday/Thursday Golf Group here in Rochester, Minnesota.  SJU and the Mayo Medical Center was blessed to have Judy/Mike.  God Bless...

Mike was a fantastic scientist and even better human being. He was also a role model for an uncountable number of students and junior investigators over the years and will be missed by his many friends and colleagues.

Dear Judy and Family,

I am so sorry to hear about Mike's passing. 

Mike had a great passion for life! He had a great love for books and learning.

I will always remember running into Judy and Mike at the "Tattered Cover" book store in downtown Denver. I had just moved to Denver, and certainly did not expect to see two friends from Rochester. I recall that Judy and I spoke for about two hours, while Mike perused every aisle of the bookstore!

Mike had a strong sense of community service. He and Judy were active in leading and supporting numerous charitable activities in the area. I am personally very grateful for the way Mike and Judy supported Our Lady of Guadalupe Free Clinic over the years.

My prayers are with you,

Dave Plevak

We will miss seeing Mike at the Canadian Honker. He was an amazing man with a wonderful attitude towards life.

The Powers Family

Judy, What I remember most about Mike are his great hugs and his gigantic smile.  Having the chance to get to know both of you  through Holy Ground was a very special.  He was also a kindred "Irish soul" and celebrating St Pat's Day was a special bond we shared.  Love, Mary Jo 

Judy, Mary and I are saddened by Mike's passing.  You and he were great Oak Cliff neighbors, and we remember the great job he did in getting everyone organized to support the project that involved the renovation of the siding on our units. This was no small feat, given the expense and the potential for differences of opinion with regard to colors.  As a member of the Rotary Club of Rochester, I am also mindful that during his term as club president, he began the continuing tradition of recitation of the Rotary "4 way test" at the start of our Club's meetings, something that prior to that time had not been done.  Mike was a smart, kind and unpretentious human being who will be greatly missed.  Our condolences to you and the rest of the family.            

Dear Judy and family,

What a beautiful memorial tribute to Mike.I am so sorry that you have to lose him, even after 60 years. He gave so much. I got to know some about you too, Judy. 💙

Love and Friendship,


To Judy and her family,

     We were so sorry to hear about Mike.  We have fond memories of the time we spent together at Pax Christi.  One very rainy night at a choir picnic (when didn't it rain at a choir picnic?) Mike was talking our daughter, Christine, about what she wanted to major in when she got to college.  Because of her love of math, he suggested statistics.  Five years later he hired her and twenty-eight years later she is still at Mayo.  We will always be grateful to him for his guidance.  May he rest in peace.     Mary and Quint Lohse

I always remembered Mike and Judy from Pax Christi.  They were so kind.  My prayers are with the whole family at this difficult time.  RIP Mike.

The two Irishmen are having a good laugh together. Thanks for your love and friendship. 
Mary Clare Doran

We have loved you both for more than 50 years.  Mike's light of deep caring and generosity has gone out and the world is less.  We feel his loss.  You and your family are in our thoughts and prayers.  With all our sympathy and love, Joe and Barbara

God has taken a good man home. My most fond memory of him was when he introduced us  to Jameson while on a trip to Ireland. Love & prayers to Judy and family.

Dear Judy,

Jane and I were so very sorry to hear that Mike had passed away.  He was a friend and a critical supporter during my short tenure as department chair and turned out to be much more successful when he took over as chair.  His  emphasis on independent statistical research by the staff and his insistence on respect for their scientific accomplishments were key.  However, Mike’s most impressive accomplishment, to my mind, was his ability to interact with and lead all of the disparate elements of our department.  That rested, in turn, on his unfailingly positive approach to all manner of challenges.  Indeed, Mike will be remembered as a positive influence on a great many lives, including mine.



Sean and Liam,

I always think of your parents and mine as young, involved, supportive and positive. We are very blessed. I am sorry for your loss. Offering prayers for Mike and all of you. 


My sincere condolences to the family of Mike O'Fallon, a well-respected colleague and friend to many at Mayo Clinic. Mike and Judy welcomed me and my family as I joined Mayo Clinic Biostatistics many years ago, and their openness and generosity made a huge impact on our lives. Mike's legacy lives on in the hearts and memories of his many friends at Mayo, in Rochester, and across the nation. He led a life of impact, trust, and friendship. So grateful to have been part of his life.