The 36-year-old Sawa, who led Japan to the title four years ago in Germany as tournament MVP and top scorer, was one of 23 players selected by coach Norio Sasaki for the June 6-July 5 competition in Canada.
It will be the sixth consecutive World Cup for Sawa, who was named 2011 World Player of the Year.
"As this is her sixth World Cup, I am counting on her to be a leader," Sasaki said.
Sawa has played the full 90 minutes in the first five games of the season for her club team.
Japan begins its title defence against Switzerland on June 8 in Vancouver, followed by Cameroon four days later before moving to Winnipeg to face Ecuador on June 16.
Seventeen of the 23 players named have prior World Cup experience. Former Asian Player of the Year Aya Miyama will continue to captain the team.
Goalkeepers: Miho Fukumoto (Okayama Yunogo Belle), Ayumi Kaihori (INAC Kobe Leonessa), Erina Yamane (JEF United Chiba)
Defenders: Yukari Kinga (Kobe), Megumi Kamionobe (Albirex Niigata), Azusa Iwashimizu (NTV Beleza), Aya Sameshima (Kobe), Saori Ariyoshi (Beleza), Kana Kitahara (Niigata), Yuri Kawamura (Vegalta Sendai), Saki Kumagai (Lyon)
Midfielders: Homare Sawa (Kobe), Kozue Ando (Frankfurt), Aya Miyama (Okayama), Nahomi Kawasumi (Kobe), Mizuho Sakaguchi (Beleza), Asuna Tanaka (Kobe), Rumi Utsugi (Montpellier), Asano Nagasato (Turbine Potsdam)
Forwards: Shinobu Ono (Kobe), Yuki Ogimi (Wolfsburg), Yuika Sugasawa (Chiba), Mana Iwabuchi (Bayern Munich)