Splittorff, 64, was hospitalized on May 16 for treatment of oral cancer and melanoma but recently returned home.
Survivors include his wife, Lynn; a daughter, Jennifer, and a son, Jamie.
The family notified the Royals that visitation will be next Monday from 5-8 p.m. CT at the First United Methodist Church, 301 SW Woods Chapel Road. Funeral mass will be next Tuesday at 11 a.m. at the St. Robert Bellarmine Catholic Church, 4313 SW State Route 7. Both churches are in Blue Springs.
In lieu of flowers, the family is asking for donations to be made to: St. Mary's Medical Center Foundation, 201 NW R.D. Mize Rd., Blue Springs, Mo. 64014
Splittorff spent his entire 15-year Major League career with the Royals and had a 166-143 record and 3.81 ERA in 429 regular-season games. He played in four postseasons, 1976-77-78 and 1980, reaching the World Series in the latter year. His postseason mark was 2-0 with a 2.79 ERA. Both wins were against the Yankees, in 1976 and '77.
"This is a very difficult day for our organization due to the passing of Paul Splittorff," said Royals owner and chief executive officer David Glass. "My prayers go out to Lynn, Jennifer and Jamie, who like all of us will miss him terribly. Paul was a lifer as a Kansas City Royal, first as a stalwart on the field who became the winningest pitcher in franchise history and then transforming himself into an outstanding broadcaster. We will not only miss the insight and humor that he injected into every telecast, but most importantly we will miss his friendship. He epitomized class and was always a great ambassador for the Kansas City Royals."
Splittorff not only holds the Royals' career record for victories, he is the leader in starts (392) and innings pitched (2,554 2/3). He became the club's first 20-game winner in 1973, when he went 20-11. He was inducted into the Royals Hall of Fame in 1987.
"I am deeply saddened by the loss of Paul Splittorff, a lifetime Royal who was beloved by the fans of Kansas City and respected throughout our game," said MLB Commissioner Bud Selig. "The left-hander holds the most wins, starts, and innings pitched in the club's distinguished history. I admired his devotion to his craft for many years, especially when he played a key role in helping the Royals reach their first World Series in 1980. After a wonderful career on the mound, Paul represented the club in the broadcast booth with great class, serving as the voice for a new generation of Royals fans.
"Paul's great career in baseball, both on the mound and in the booth, is a testament to the hard work, preparation and sincerity that served him so well in life. On behalf of Major League Baseball, I extend my deepest condolences to Paul's wife, Lynn, children, Jennifer and Jamie, and all the fans of the Kansas City Royals."
To honor Splittorff's memory, the Royals will wear a memorial patch that says "Splitt" on a sleeve of their jerseys for the remainder of the season.
"He wasn't blessed with a 100-mph fastball, he wasn't blessed with a Bert Blyleven curve, he wasn't blessed with a tremendous changeup, but he was blessed a good brain. He knew how to pitch," said teammate and Hall of Famer George Brett. "He was blessed with a big heart and put it all on the line. He was always prepared; he was always in good shape."
Splittorff's playing career spanned from 1970-84 and after his retirement he became known to a legion of baseball and Big 12 basketball fans as a highly respected and knowledgeable broadcaster.
"He was such a pro," said Bob Davis, who teamed with Splittorff on Royals broadcasts for many years. "I didn't know him much as a player, other than at a distance, but I saw him as a broadcaster. He started out with high school games and paid his dues. I think there's a generation now in Kansas City that really only knows him as a broadcaster. They know that he played but don't remember him as a player and I think that's a pretty tremendous accomplishment when you can do that in two careers."
Frank White, a teammate who took over in the TV booth during Splittorff's illness, remembered him fondly.
"Paul [was] probably one of the more underrated guys on our team," White said. "He not only played for 15 years but he won some huge games for us. I have memories of him beating the Yankees in Game 3 of the 1980 playoffs to get us to our first World Series."
Splittorff, with relief help from Dan Quisenberry and home runs by Brett and White, beat the Yankees, 4-2, in New York to sweep the American League Championship Series -- finally, after the Royals had lost to the Bronx Bombers three times in the '70s.
"Splitt was a great teammate, a great professional, [he] taught me a lot about catching," said Jamie Quirk, another teammate on those Royals teams. "I was a converted catcher and used to sit with him and go over hitters. He had a big influence in my career.
"You had George Brett, who's the No. 1 Royal. Frank White is probably No. 2. No one has ever gotten past that, but I would still put Splitt No. 3. In Kansas City he's gotten his due because he was a former player to broadcast for 20-something years and first as a pitcher, but I don't think people realize some of the things he accomplished."
Splittorff this year was working in his 24th season as a television analyst for FOX Sports Kansas City. However, his appearances on Royals broadcasts in the past three years had been limited because of difficulties with his voice.
"I'm sure he was getting frustrated, I'm sure he heard himself on the broadcasts and wasn't happy with the way things were going, but give him credit, he wanted to stay with it," Brett said.
"That was his life. He couldn't pitch any more but he could broadcast. He was very insightful and knowledgeable about the game. I thought he made himself a great broadcaster. He made himself a great pitcher with hard work. Everything about him was 100 percent and I'm sure he fought this cancer with 100 percent also."
In press boxes, Splittorff was a familiar figure studying players and statistics before games to give depth to his analysis. He appreciated a good laugh but could be critical when warranted.
"He was funny, he had a sense of humor," Davis said. "We shared so many laughs. When one of us made a fluff on the air, the other guy would get on the other one and it became a funny thing."
"The competitive fire that he had as a player would come out once in a while. I remember how devastated he was the first time the Royals lost 100 games. That really hit him hard that that had happened to his team."
Splittorff missed some basketball assignments during the 2008-09 season because of his medical problems. An intensely private person, he kept those issues largely to himself.
His difficulties became evident to Royals fans during the Opening Day telecast from Chicago on April 8, 2009. He teamed with Ryan Lefebvre to do the game but had problems with his voice and returned home to Kansas City.
Typically, Splittorff worked hard to recover, undergoing speech therapy in an effort to recapture his voice. He appeared in pre- and postgame broadcasts this year and worked in the booth during a series in Texas.
"He was the most valuable commodity that we had, I thought," Lefebvre said. "He was a celebrated former player who could do radio, television, play-by-play and he could do color analysis. Those guys don't fall out of the sky. And in the offseason he'd go do another sport -- and at a high level, Big 12 basketball."
Splittorff was a two-sport star in baseball and basketball at Morningside College in Iowa and carried the love of both sports with him throughout his life. The expansion Royals drafted him in 1968.
"He was a long shot to make it to the Major Leagues, being a 25th-round Draft pick out of a small college and he signs with a team that he'd never heard of because the Major League team wasn't operating yet," Davis said. "They sent him to Corning, N.Y., and because they didn't have a Double-A team at the time, he jumps to Triple-A Omaha. And he not only defies the odds by making it to the Major Leagues, he was extremely successful."
As a rookie in 1971, he showed his promise by recording a 2.68 ERA to go with an 8-9 record. In 1973, he went 20-11 and came close to that level in 1978, when he was 19-13.
"He knew how to pitch," Brett said. "Sometimes you have to will your way to victory and the guy with the biggest heart will win. And that's what he had."
Dick Kaegel is a reporter for MLB.com. This story was not subject to the approval of Major League Baseball or its clubs.