Natalie Koukis was chosen as head coach of the Wittenberg men's and women's swimming and diving teams in July 2004. She held the position until 2016.

Koukis has continued to elevate the program while competing in the extremely challenging North Coast Athletic Conference (NCAC). The Tiger women have finished as high as third place behind perennial NCAA Division III title contenders Kenyon College and Denison University. The men's program has also moved up to the third place position and has consistently finished in the top five in recent years. During that time, Koukis has led numerous student-athletes to All-America, Scholar All-America and All-NCAC honors.

Koukis garnered NCAC Women's Swimming Coach of the Year honors in 2006, followed by NCAC Men's Swimming Coach of the Year honors in 2008 after leading the teams to their best conference finishes in more than a decade.

Koukis came to Wittenberg after two years as head men's and women's swimming and diving coach, director of aquatics and instructor of physical education at Worcester Polytechnic Institute in Massachusetts. During her time at WPI, Koukis led both the men's and women's teams to their highest finishes ever in the New England Women's and Men's Athletic Conference. More than a dozen swimmers received special recognition, including four All-New England, five all-conference and eight academic all-conference designations. In addition, the teams set more than 20 new school records in her two seasons.

Koukis was a good fit for the position since she is no stranger to the state of Ohio or the North Coast Athletic Conference. A native of Delaware, Ohio, Koukis was a two-year letterwinner at Ohio Wesleyan University after transferring from George Washington University. She graduated from Ohio Wesleyan in 1998 with a bachelor's degree in psychology and women's studies. She also minored in sociology.

After graduation, Koukis served as an assistant men's and women's swimming and diving coach at her alma mater from 1999 to 2001. In addition, she was the head assistant coach of the Delaware U.S. Club Team between 1997 and 2001.

Prior to her arrival at WPI, Koukis served as assistant women's swim coach at Ithaca College in 2001-02, where she also served as an instructor of physical education. She also worked at Ithaca with Sport Psychology Professor Greg Shelley as a teaching and research assistant. She graduated from Ithaca in 2002 with a master's degree in exercise and sport science, with a concentration in sport psychology.

Koukis resides in Springfield with her husband, John Derr, and their daughters, Penelope, Lola and Olympia.