"Along with the citizens of Israel, my wife Sara and I would like to express our deep sorrow over the death of the president's wife, Nechama," Netanyahu said.
"We have all been praying for her recovery these past weeks, as she was bravely fighting for her life. We send our condolences to the president, his family and to the entire country. May her memory be blessed."
Mrs. Rivlin died early Tuesday at the Beilinson Hospital outside Tel Aviv, just one day short of her 74th birthday.
A statement from the first family Tuesday said: "The Rivlin family wishes to thank the people of Israel and religious leaders who have continued to be concerned about Nechama's welfare, who have sent letters and children's drawings to the hospital and the President's Residence and who have prayed for her recovery every day, every hour."
Yuli Edelstein, who succeeded Rivlin as Knesset speaker, expressed sadness on behalf of the Knesset, its members and staff.
"We all share in the great sorrow of my friend, President Rivlin and his family," Edelstein said. "With her personality and her kindness, Nechama touched everyone she met."
MK Gideon Sa'ar a close political ally of the president and a personal friend, also expressed his great sorrow: "My heart is with my friend, President Reuven Rivlin, for whom Nechama was a friend, a lover, a partner and a rock."
Opposition leader Blue and White Chairman Benny Gantz also expressed her condolences, expressed sadness. He said Nechama Rivlin was respected by Israel's society for her kindness.
"The Blue and White faction shares in the grief of the president and his family," he said. "Nechama was a wonderful, kind woman, who was respected by the entire country. May her memory be a blessing."
Tributes to Mrs. Rivlin also came from Labor Party leader Avi Gabbay and outgoing Education Minister Naftali Bennett.