Harold E. "Butch" Woolfolk (born March 1, 1960) is a former American football running back and kick returner who played in college for the University of Michigan (1978–1981) and in the National Football League (NFL) for the New York Giants (1982–1984), Houston Oilers (1985–1986) and Detroit Lions (1987–1988). Woolfolk attended Westfield Senior High School in Westfield, New Jersey. Woolfolk led Michigan in rushing three straight years and set the school record with 3,850 rushing yards while playing for the Wolverines from 1978 to 1981. As a sophomore in 1979, he was the Big Ten Conference scoring champion, and he went on to become a three-time first-team All-Big Ten selection. He had his best season as a senior at Michigan, winning the 1981 Big Ten rushing title and falling just 10 yards short of Rob Lytle's single-season rushing yards record. He was also selected in 1981 as the Most Valuable Player of both the Rose Bowl played January 1, 1981, and the Bluebonnet Bowl played December 31, 1981, as well as the Wolverines' team MVP for the season.
Woolfolk also excelled in track. He was named an All-American in 1980 and won nine Big Ten track and field championships both as an individual and relay race team member. He continues to hold the Michigan outdoor 200-meter record. He was also a member of relay teams that hold numerous U-M and Ferry Field all-time records.
Woolfolk played seven seasons in the NFL. As a rookie in 1982, he finished third in the NFL in all-purpose yards. And in 1983, he set an NFL record with 43 rushing attempts in a single game. He was also fifth in the NFL in receptions in 1985. Woolfolk was plagued with injuries during his NFL career and was able to play in 16 games only twice—in 1983 and 1985. In both of those years, he accumulated at least 1200 yards from scrimmage. He also had seven 100-yard games—five receiving and two rushing.