Notable people who have attended Séances and believed in Spiritualism include:

The United States President Abraham Lincoln and his wife Mary Todd Lincoln
The social reformer, Robert Owen
The journalist and pacifist, William T. Stead William,
who died on the Titanic after being advised not to go
The Prime Minister of Canada for 22 years, Mackenzie King,
spiritual contact & political guidance thru deceased mother.
US President Franklin D. Roosevelt
The journalist and author, Lloyd Kenyon Jones
The physician and author of Sherlock Holmes and other books including Spiritualism, Arthur Conan Doyle
Victorian Poet, Elizabeth Barrett Browning
America's Sleeping Prophet, Edgar Cayce
The Father of Modern Spiritualism and author of
Spiritualist Declaration of Independence in 1851,
Andrew Jackson Davis
Pioneering Physical Medium, George Davis Dexter, M.D.
Supreme Court Judge John W. Edmonds
Congressman and Senator Hamlin Garlan
Author, Pulitzer Prize winner Emma Hardinge Britten
Early Advocate of Spiritualism Professor,
Author, Speaker, Robert Hare
Author, Poet, Statesman Victor Hugo
Abnormal psychology and psychical research,
Professor James Harvey Hyslop, Ph.D. LL.D.
Chemist and Parapsychologist, Dr. Alexander Imich
Philosopher and Psychologist Professor
Harvard Professor, William James, M.D.
Pioneer studies on Death and Dying,
Dr. Elisabeth Kubler-Ross, M.D
Seer and Adept, author of The OAHSPE Bible,
John Ballou Newbrough
"The White Crow," Medium Lenora Piper
Founder of  Pratt Institut, Morris Pratt
Founder of Astara Institute, Robert Chaney
Author Mark Twain, was advised not to go with his brother
on a river trip, told his brother not to go, his brother died.
Queen Victoria
Julius Caesar, advised when he would be assassinated
Trance and Music Medium Jesse F. Shepard
Founder of The Swedenborg Society, Emanuel Swedenborg
Pulitzer Prize winning author, Booth Tarkington
Co-originator with Charles Darwin Theory of Natural Selection, Evolutionary Biologist,
Dr. Alfred Russell Wallace
Famous Russian ballet dancer, Vaslav Nijinsk
Direct Voice Medium, Sophia William
Direct Voice Medium, Edda Wriedt
Direct Voice Medium, Rev Florence Harwood Becker
World famous practicing Medium,  Author Ford
Famous Medium "JFK Prophecy" and author, Jeane Dixon
President Ronald Reagan and his wife, Nancy Reagan
Autobiography of a Yogi
by Mukunda Lal Ghosh Yogananda,
Paramahansa Yogananda, who said . . .

Self-realization is the knowing in all parts of body, mind, and soul that you are now in possession of the kingdom of God; that you do not have to pray that it come to you; that God's omnipresence is your omnipresence; and that all that you need to do is improve your knowing

and thousands more . . .famous, infamous, and mundane.

"When I tell the truth, it is not for the sake of convincing those who do not know it...but for the sake of defending those that do."
--William Blake

Scientists who have researched, participated in Séances and believed that contact with the dead is a reality include:

Chemist and physicist, inventor of several items like vacuum tubes, discovered thallium and helium, Sir William Crookes
the inventor of the sewing machine, Elias Howe
the inventor of the radio, Guglielmo Marconi
the inventor of the telephone, Alexander Graham Bell
the inventor of television technology, John Logie Baird,
who claimed to have contacted the spirit of the inventor Thomas Edison

In 1978, future Prime Minister of Italy, Romano Prodi took part in a Séance in which the name Gradoli, a town and road leading to Rome, was the location where politician Aldo Moro was being detained after being kidnapped.  Trusting the  information, they did search for him, but were unable to find him.  After he was murdered, they did find that he had been incarcerated there.

Thomas Glendenning Hamilton
(November 27, 1873 - April 7, 1935) was a Canadian doctor, school board trustee and member of the Manitoba legislature.  He is best known however for the thousands of photographs he took during Séances held in his home in Winnipeg in the early 1900s.  His wife, Lillian May Hamilton, and his daughter, Margaret Hamilton Bach, were co-researchers and continued this enquiry into life after death after he died.

The Hamilton family left a rich legacy.  Lillian compiled several scrapbooks of photos and other materials for her children.  Margaret, however, was the one who collected all the papers from the family dealing with their paranormal research and deposited these with the University of Manitoba Archives and Special Collections.