LONDON, Jan. 22— Edith Haisman, the oldest survivor of the sinking of the Titanic in 1912, died on Monday night at a nursing home in Southampton, England. She was 100.

Karen Kamuda, the vice president of the Titanic Historical Society, said in a telephone interview today from Indian Orchard, Mass., that Mrs. Haisman's death left 7 of the 705 survivors still living, 3 in the United States and 2 each in Britain and France.

Mrs. Haisman, who was 15-year-old Edith Brown at the time of the sinking, was the last survivor who was a teen-ager in 1912. The ones who are still alive ranged in age from 9 weeks to 8 years old at the time of the disaster, which claimed more than 1,500 lives.

She was a guest of honor last August on a pilgrimage cruise to the spot 400 miles off the Newfoundland coast where the liner, on its maiden voyage, hit an iceberg on the night of April 14-15, 1912.

In 1995 she took part in the opening of a memorial garden at the National Maritime Museum in Greenwich, London, with a granite monument commemorating the victims, and in 1993 she appeared in public in Southampton to receive a gold watch thought to be her father's from the head of the American company that had salvaged it from the wreckage.

She had last seen the watch protruding from the waistcoat pocket of her father, Thomas William Solomon Brown, 60, a hotel owner from Worcester, a suburb of Cape Town, South Africa. He was taking his wife, Elizabeth, and his daughter Edith to Seattle, where he intended to open a new hotel. In the hold of the cruise liner were tableware, furnishings and 1,000 rolls of bed linen for the new enterprise.

In a series of interviews in her later years and a biography, ''A Lifetime on the Titanic,'' published in 1995, Mrs. Haisman gave a vivid account of the ship's final moments, although some details have been called into question.

Mrs. Haisman said she remembered that her father was dressed in an Edwardian dinner jacket, stabbing the cold night air with his cigar and sipping from a snifter of brandy on the deck of the listing ship as she and her mother were being winched 70 feet down into a lifeboat.

Mrs. Haisman said that she never forgot the horror of that night and the loss of her father and that even in her later years she suffered nightmares in which she heard the screaming of the drowning victims in the Atlantic. It was 11:40 P.M. when she recalled being jolted in her three-berth stateroom. ''Father appeared a few minutes later,'' she recalled. ''He told us: 'You'd better put on your life jackets and something warm, it's cold on deck. It's just a precaution. We've struck an iceberg -- it's nothing much. The steward in the corridor says it's nothing to worry about.' ''

They hurried through the corridors, leaving behind in their haste her mother's jewelry case, 400 gold sovereigns and a roll of bank notes on top of a bunk. ''We waited for ages on the boat deck for someone to tell us what to do. The ship's band was playing ragtime. They played to keep our spirits up. It was so brave of them. Everybody kept saying: 'She's unsinkable. She won't go down.'

''Father kissed us and saw us into Lifeboat 14. Up to 50 people got in as it swung perilously over the side. One man jumped into the boat dressed as a woman. As we rowed away from the ship, we could still hear the band playing, but now it was hymns.'' She watched the mighty liner go down. ''We were almost six hours in the lifeboat and during that time we had no water and nothing to eat. I kept wondering if my father had got off the ship -- that's all I could think of.''

She and her mother were picked up by the Cunard liner Carpathia and taken to New York, where they left on a train trip to Seattle to spend time with an aunt of Mrs. Haisman's, who lived there and had inspired the move to the West Coast. They soon returned to South Africa, where five years later Edith married Fred Haisman, a shipbuilder's engineering draftsman from London.

Married for 60 years, the couple lived in South Africa, Australia and Southampton, where Mr. Haisman worked in the boatyard. They had 10 children.

Ms. Kamuda, of the Titanic Historical Society, said Mrs. Haisman had ''elaborated'' her story over the years, adding details about what her father was wearing, for example.

''This is not a criticism of Mrs. Haisman,'' Ms. Kamuda said. ''On the contrary it is only to point out how our memories fail us as time passes and numerous outside influences shape our lives.''

Mrs. Haisman did not share the concern of some survivors and many curators and historians over efforts to salvage mementos from the wreck and to raise parts of the ship itself. The 18-carat pocket watch that she said was her father's had been found in a purser's black leather portmanteau during a dive in 1987.

R. M. S. Titanic of Southport, Conn., the company that exhibits artifacts from the ship and that has drawn charges of exploiting the disaster from Ms. Kamuda and others, had the watch attached to a sterling silver plate inscribed with the words, ''What better use for scientific technology than to reunite a father with his child.'' The chairman of the company, George Tulloch, presented it to Mrs. Haisman in Southampton in December 1993.

By her bed in the nursing home stood a photograph of her father in a straw boater, stiff collar and bowtie.

Mrs. Haisman was born on Oct. 27, 1896. She is survived by four sons, two daughters and more than 30 grandchildren and great-grandchildren.

Photo: Edith Haisman. (Associated Press, 1966)