Monson, who was 90 years old, had served as president of the Mormon church since 2008.
Thomas S. Monson, president of The Church of Jesus Christ of Latter-day Saints, died late Tuesday at his home in Salt Lake City, the church said in a statement.
Monson, 90, had served as president of the Mormon church since 2008.
"To the more than 16 million members of the church around the world, President Monson was an example of one who followed Jesus Christ," the statement said.
Monson, who spent 45 years as an apostle, was known for making personal visits to homes or hospital bedsides or taking time to write a letter or make a telephone call, the church said in a tribute on its website. His name forever will be linked to compassionate endeavors, service to others," it said.
His biggest change to the church was lowering the age of full-time missionaries in 2012 in order to boost enrolments from younger men and women, according to the Salt Lake City Tribune.
It hailed Monson as an "affable leader, folksy preacher and care-taking friend."
Monson was also an ardent football fan, NBC affiliate in Utah KSL reported, particularly of the University of Michigan Wolverines.