Theo Cobb Landon, the widow of Gov. Alfred M. Landon of Kansas and the mother of Senator Nancy Landon Kassebaum, Republican of Kansas, died on Sunday at her home in Topeka. She was 97.

Mr. Landon, the Republican candidate for President in 1936, died in 1987 at the age of 100 after 57 years of marriage.

Six decades ago, Mrs. Landon drew press coverage around the country by refusing to join her husband on the hustings in his quest to unseat President Franklin D. Roosevelt. Mrs. Landon insisted that she could not campaign and also guard the privacy of her family. She had two young children to look after and, she told the press, she was needed at home.

Besides Senator Kassebaum, Mrs. Landon is survived by a son, John C.; six grandchildren, and six great-grandchildren.

Theo C Landon