Michelle M. Marciniak (born October 29, 1973) is a former All-American collegiate and professional basketball player who played point guard in the Women's National Basketball Association (WNBA). As a floor general, Marciniak competed for two national championships during her three-year career at the University of Tennessee. She led the Tennessee Lady Vols to their fourth national championship and, in 1996, was named most valuable player in the Final Four Women's Tournament in Charlotte, North Carolina.

She later was the recruiting coordinator/assistant coach of the women's basketball team at the University of South Carolina from 2003 to 2008. Marciniak was responsible for two back to back top recruiting classes, rated #18 in 2007 and #7 in 2008, the highest ranked class ever recruited at South Carolina.

Marciniak is currently the co-founder and co-chief executive officer of Sheex in Marlton, New Jersey, a performance fabric bedding company.

Marciniak was born in Silver Spring, Maryland, on October 29, 1973.

Marciniak attended Allentown Central Catholic High School in Allentown, Pennsylvania, where she played high school basketball in the highly respected East Penn Conference. In 1991, as an Allentown Central Catholic High School senior, she was named National Player of the Year by Parade magazine, Naismith National Player of the Year, and Gatorade National High School Player of the Year. In February 1991, Sports Illustrated profiled Marciniak in an article titled "She's the Ponytailed Princess of the Hoop," which covered her performance as a high school junior at Allentown Central Catholic High School. She scored 3,025 points for Allentown Central Catholic High School, and the school later retired her number 23 jersey number in recognition of her extraordinary high school basketball achievements.

After a year at Notre Dame, Marciniak transferred to Tennessee, where she quickly became a leader in its dominant team under head coach Pat Summitt. Summitt had recruited her at Allentown Central Catholic High School, where she went into labor as she was sitting in the Marciniaks' home on a recruiting trip. Summitt quickly wrapped up the visit and flew back to Knoxville, where she gave give birth to her son, Tyler. "Spinderella", as Marciniak was affectionately known because of her free wheeling, spinning, and slashing style, became a crowd favorite at Tennessee. She scored over 1,000 points and remains ranked among Tennessee's top ten all-time in assists and three-point scoring, despite only playing three seasons.

With Marciniak at point guard, the Lady Vols won consecutive Southeastern Conference championships in 1995 and 1996. In the NCAA Women's Division I Basketball Championship, Tennessee came in second to the Connecticut Huskies. In the 1995-1996 season, Tennessee wasn't expected to be as strong, but the team lost just four games during the regular season and returned to the Final Four, where they faced a rematch with Connecticut. In the game, Marciniak led the team to an 88-83 overtime victory, then avenged an earlier loss to Georgia to claim Tennessee's fourth national championship. During the season, Marciniak became the focused leader and played a methodical style of basketball that Pat Summitt demanded from her point guards. Marciniak was chosen the NCAA Division I basketball tournament Most Outstanding Player for her play. She graduated from the University of Tennessee in 1996 with a degree in psychology.

Marciniak was named to the USA U18 team, then called the Junior World Championship Qualifying Team, in 1992. The team competed in Guanajuato, Mexico, in August 1992. The team won their first four games, then lost 80–70 to Brazil, finishing with the silver medal for the event, but qualifying for the 1993 world games. Marciniak averaged 6.8 points per game during the event.