Natalie Williams played three seasons for the Portland Power in the American Basketball League (ABL). She was traded to the Long Beach Stingrays in April 1998, but when the team folded, she was reassigned to the Power. She was a two-time All-ABL first team selection, the 1998 ABL M.V.P., finished her first season as the league's top rebounder, averaging 12.5 rebounds per game, and on January 9, 1998, she grabbed a league record 22 rebounds.
After the ABL folded, she was selected by her hometown team, the Utah Starzz in the first round (third pick overall) of the 1999 WNBA Draft on May 4, 1999.
She played with the Starzz from 1999 to 2002. However, just a few weeks prior to the start of the 2003 season, she was traded to the Indiana Fever in a multi-player deal on May 1, 2003.
Prior to the start of the 2005 season, Williams announced that she would retire after the season ended, saying that she will concentrate on raising her adopted twins, as well as serving as an assistant coach for Skyline' high school Girls basketball team in Salt Lake City, Utah, and launching a new career in the real estate business. She is remembered by fans as one of the best rebounding power forward in the early history of the WNBA.
Williams was invited to be a member of the Jones Cup team representing the USA in 1996. She helped the team to a 9–0 record, and the gold medal in the event. Williams averaged 9.1 points per game. She also recorded 7.0 rebounds per game, highest on the team.
Williams was named to the USA national team in 1998. The national team traveled to Berlin, Germany in July and August 1998 for the FIBA World Championships. The USA team won a close opening game against Japan 95–89, then won their next six games easily. In the semifinal game against Brazil, the USA team was behind as much as ten points in the first half, but the USA went on to win 93–79. The gold medal game was a rematch against Russia. In the first game, the USA team dominated almost from the beginning, but in the rematch, the team from Russia took the early lead and led much of the way. With under two minutes remaining, the USA was down by two points but the USA responded, then held on to win the gold medal 71–65. Williams averaged 12.3 points per game, second highest on the team, and averaged 9.6 rebounds per game, highest on the team.
In 2002, Williams was named to the national team which competed in the World Championships in Zhangjiagang, Changzhou and Nanjing, China. The team was coached by Van Chancellor. Swoopes scored 16.9 points per game, second highest on the team and recorded a team-high 24 steals. The USA team won all nine games, including a close title game against Russia, which was a one point game late in the game. Williams averaged 5.9 points per game.