|Date of birth||April 13, 1945|
|Place of birth||Oklahoma City, Oklahoma, United States|
|Date of death||July 21, 1970(aged 25)|
|Place of death||Thua Thien, South Vietnam †|
|NFL draft||1968 / Round: 8 / Pick 199|
|Allegiance||United States of America|
|Service/branch||United States Army|
|Years of service||1968–1970|
|Unit||101st Airborne Division|
James Robert "Bob" Kalsu (April 13, 1945 – July 21, 1970) was an All-American tackle at the University of Oklahoma and an eighth-round draft pick by the Buffalo Bills of the American Football League in 1968.
Kalsu was a starting guard in 1968. He played the entire season and was the Bills' team rookie-of-the-year. Following the 1968 season, to satisfy his Reserve Officers' Training Corps (ROTC) obligation, he entered the Army as a Second Lieutenant and arrived in Vietnam in November 1969 as part of the 101st Airborne Division. He was killed in action on July 21, 1970 when his unit came under enemy mortar fire at FSB Ripcord near the A Shau Valley. His family, out of respect, refused to talk in detail about the circumstances surrounding his death.
When he had left for Vietnam, Lieutenant Kalsu had to say goodbye to his wife, Jan, and his daughter Jill. On July 23, 1970, two days after his death, Jan Kalsu gave birth to his son, James Robert Kalsu Jr, at the Kalsu home in Oklahoma City. Mrs. Kalsu was informed of her husband's death only hours later. Kalsu and former Cleveland Brown Don Steinbrunner were the only professional football players to lose their lives in the Vietnam War.
- FOB Kalsu in Babil, Iraq, was named after him.
- In 1999, NFL Films produced a feature on Kalsu that was nominated for an Emmy Award.
- In 2000, the Buffalo Bills added Kalsu's name to the Buffalo Bills Wall of Fame.
- In 2002, the replacement company at Fort Campbell was named in honor of him – 1LT J. Robert Kalsu Replacement Company.
- Del City High School's football stadium bears his name.
- There is a CrossFit Work Out of the Day (WOD) named in his honor.
- Pat Tillman
- Harry O'Neill - One of the two Major League Baseball players killed in World War II.
- Tim James – Basketball player who left his professional sports career and enlisted in the United States Army on September 12, 2008.
- Other American Football League players
- Don Steinbrunner
- Rockin’ the Rockpile: The Buffalo Bills of the American Football League, p.567, Jeffrey J. Miller, ECW Press, 2007, ISBN 978-1-55022-797-0
- Rockin’ the Rockpile, p.513