The 1991 Little League World Series took place between August 20 and August 24 in South Williamsport, Pennsylvania. In the championship game of this 45th Little League World Series, the Hsi Nan Little League of Taichung, Taiwan, defeated the San Ramon Valley Little League of Danville, California.

United States	International
Hamilton, Ohio Central Region Westside American Little League	Glace Bay, Nova Scotia Canada Region Glace Bay Little League
Staten Island, New York East Region South Shore American Little League	Dhahran, Saudi Arabia Europe Region Arabian American Little League
Dunedin, Florida South Region National Little League	Taichung, Taiwan (Chinese Taipei) Far East Region Hsi Nan Little League
Danville, California West Region San Ramon Valley Little League	San Cristóbal, Dominican Republic Latin America Region Luis Montas Little League

• Republic of China, commonly known as Taiwan, due to complicated relations with People's Republic of China, is recognized by the name Chinese Taipei by majority of international organizations including Little League Baseball (LLB). For more information, please see Cross-Strait relations.

	Quarter-finals				Semi-finals				Final
	August 20
	Dominican Republic	2
					August 22
	Taiwan	3
					Taiwan	17
	August 21
					Canada	1
	Canada	5
									August 24
	Saudi Arabia	3
									Taiwan	11
	August 20
									California	0
	Ohio	0
					August 22
	New York	8
					New York	4
	August 21
					California	13			Third place
	Florida	4
									August 23
	California	5
									Canada	0
									New York	16

	Games A & B				Game D
	August 21
	Dominican Republic	10
					August 23
	Ohio	0
					Dominican Republic	3
	August 22
					Florida	2
	Florida	23
	Saudi Arabia	7
					Game C
					August 23
					Ohio	5
					Saudi Arabia	1

1991 Little League World Series Champions
Hsi Nan Little League Taichung, Taiwan

• Michael Cammarata (Staten Island, New York) – New York City Fire Department firefighter, died during the September 11 attacks^[1]
• Ron DeSantis (Dunedin, Florida) – Governor of Florida, former member of the United States House of Representatives
• Lin Wei-chu (Taiwan) – Competed in the 2004 Summer Olympics and played for the Hanshin Tigers of Nippon Professional Baseball's Central League from 2003 to 2013
• Jason Marquis (Staten Island, New York) – MLB pitcher from 2000 to 2015
• Brian Esposito (Staten Island, New York – MLB catcher in 2007 for the St. Louis Cardinals and 2010 for the Houston Astros

• 1991 Little League World Series at the Wayback Machine (archived September 30, 2017)
• Line scores for the 1991 LLWS at the Wayback Machine (archived August 31, 2017)