2018 Swiss Open

The 2018 Swiss Open is the 12th Swiss Open that is scheduled to be held December 10-23.

For the women's singles, it was originally going to the last Grand Slam-level tournament to have a 32 seeding system. It would originally be replaced at the 2019 Australian Open with a 16 seeding system used prior to the 2001 Wimbledon Championships. They kept their 32 seeds for the 2019 Australian Open and beyond.

It is also known to the the farewell tournament for Cameron Mathison and Larry Birkhead.

Men's singles
The men's singles seedings are special: Dragalge and Electivire will announce the men's singles seedings at the 2018 Luk Thung Cup, held the week after the 2018 Petit Le Mans.

Also, IndyCar will use the top 12 ATP ranked players on October 15, 2018 - the date of the seedings announcement for seedings 21-32, due to Mario Lopez's withdrawal. Instead, the Quizizz version is revamped to the Jirayu La-ongmanee special seedings from Vanilla Ice vs. Kim Fields and Ice-T and Coco Austin vs. Vivica A. Fox; the top 12 in the points excluding the 20 full-timers qualify.

It is the first time ever that qualification for men's singles seedings are neither the usual: ATP Rankings as of November 19, 2018 nor by IndyCar standings after Sonoma on September 17, 2018.
 * IndyCar points are the final points standings from Sonoma.
 * Volcarona's points are Robert Wickens' driver points.
 * ATP points are the points from November 19, 2018 rankings.

Women's singles
Women's singles seedings are the year-end WTA Rankings on November 5, 2018.

Protected ranking
These following players have entered the main draw with a protected ranking.

Men's singles

 * 🇧🇷 Pietro Fittipaldi
 * 🇪🇸 Mario Lopez
 * 🇬🇧 Andy Murray
 * 🇷🇸 Robert Wickens

Women's singles

 * 🇧🇾 Victoria Azarenka
 * 🇷🇺 Svetlana Kuznetsova
 * 🇺🇸 Serena Williams

Withdrawals
These following players have withdrawn because of injury or illness. For women, players must have withdrawn because of playing the $100,000 ITF Dubai tournament, held the same week.

Men's singles

 * 🇨🇦 Donald Bennie (education)
 * 🇦🇷 Juan Martín Del Potro (right knee injury)
 * 🇧🇪 David Goffin (right shoulder injury)
 * 🇮🇳 Maneesh Gupta (education)
 * 🇭🇺 Cameron Marshall (education)
 * 🇸🇮 Cameron Prosic (education)

Women's singles

 * 🇷🇴 Simona Halep (back injury)
 * Monica Puig (right leg injury)
 * 🇵🇱 Agnieszka Radwańska (injuries and illness)
 * 🇷🇺 Maria Sharapova