Coach Walter Olsewski has been the head coach of the Manhattan College women's swimming team since 1997.  Olsewski also became head coach of the men's team when the program was reinstated to varsity status in 2008.  During the 2007-08 season, he racked up his 100th win as the women’s coach.

In the spring of 2009, the Lady Jaspers were named to the College Swimming Coaches Association of America (CSCAA) Academic All-America Teams for the 22nd consecutive semester.  The squad produced a 3.27 cumulative grade point average, which ranked 66th out of 110 Division I swim teams in the CSCAA.  During his career, he has coached several MAAC All-Academic selections.  

Prior to coaching swimming at Manhattan, Olsewski was the head swim coach at Hicksville High School for 13 years, beginning in 1976.  While at Hicksville, he posted an overall dual meet record of 198-178-4.  During his tenure, three Hicksville swimmers earned All-America honors, 14 won All-New York State Awards, 56 won All-Nassau County Awards, 24 earned All-Conference Awards and 22 received All-Division Awards.  He helped produce two New York State Champions and a 1985 New York State Girls Championship.

He has been very active in the swim industry.  He is the former treasurer and chairman of National Interscholastic Swimming Coaches Association (NISCA) and was presented with the NISCA Outstanding Service Award in 1998 for lifetime service in swimming community.  Additionally, he served as secretary and treasurer for New York State Swim Coaches Association, held chairman position of NYS Swimmer/Diver Scholar Athlete Committee, served as official scorer at the New York State Swimming & Diving Championships, has been President of Nassau County Swim Coaches Association since 1980, and served as President of the Long Island Swim Coaches Association since 1986

A 1968 Manhattan graduate with a degree in physical education, Olsewski, a Brooklyn native, was a four-year letterwinner on the Manhattan College swim team under head coach Jack Carey.  During his senior season, Olsewski posted consecutive doubles wins against William Patterson College and Stony Brook.  He had the top 50 freestyle time on the team during that season, and received the Jasper Award, awarded annually to the senior swimmer with the highest grade point average.  He was selected to the Dean’s List all four years at Manhattan.

Olsewksi began his teaching career in 1968 in the Central Islip Public School District at F.J. O'Neill Elementary School.  He retired from teaching in that district in July 2000.  While with the Central Islip School District, he served 12 consecutive terms as Treasurer and Membership Chairperson for the Central Islip Teachers Association

In addition to his bachelor’s degree, Olsewski earned a master's degrees in Health Education from Adelphi University and an Administration of Elementary Schools degree from Washburn University.

Olsewski resides in Medford, N.Y. with his wife, Susan.  Their son Sean graduated from Manhattan in 1997 with a degree in sociology.