Daniel Knowles MacFayden (June 10, 1905 – August 26, 1972) was an American starting and relief pitcher in Major League Baseball.

His father had died when he was four years old, and they went to live with his mother Sarah's brother, building contractor Joshua Knowles.

On May 7, 1924, pitching for Somerville against Everett High, MacFayden struck out between 31 and 33 batters in 17 innings while giving up only four hits.

In 1924 he played for the Osterville town team in the Cape Cod Baseball League (CCBL) and posted a 9–2 record.

Playing alongside his Somerville High teammate and fellow future-major leaguer Shanty Hogan, the pair led Osterville to the league title.

[1] MacFayden was signed by Boston Red Sox owner Bob Quinn after he saw him pitching in the Twilight League.

He did not play in the minor leagues but went straight to the Red Sox, making his debut on August 25, 1926, against the Detroit Tigers as a reliever.

After one more relief stint, MacFayden made his first start against the legendary Walter Johnson of the Washington Senators on September 4, 1926.

In 1928, he was the Boston Red Sox's Opening Day pitcher, making his season debut in Griffith Stadium in Washington, D.C., with another native New Englander, President Calvin Coolidge in attendance.

The Yankees, anchored by Hall of Famers Babe Ruth, Lou Gehrig, Tony Lazzeri and Bill Dickey among position players and Hall of Fame starting pitchers Lefty Gomez, Herb Pennock and Red Ruffing on the mound went on to win 107 games and sweep the Chicago Cubs in the World Series.

After the Yankees lost the pennant to the Senators in 1933, Dan Daniel of the World-Telegram blamed MacFayden, who had a dreadful 5.88 ERA as a spot starter and reliever, for the Bronx Bomber's failure to repeat as American League champions.

MacFayden told the press he was happy to be leaving the Bronx, as he did not like the way manager Joe McCarthy (another future Hall of Famer) handled him.

The team, which was partly owned by Bob Quinn, the former Red Sox owner who first signed MacFayden, started calling itself the Boston Bees in 1936 in a bid to get the fans to forget their dismal performance.

His ERA of 2.87 ranked second best in the senior circuit, which along with his 17–13 record on a team that came in 6th in an eight-team league with 71 victories, won him votes for Most Valuable Player.

According to Charles Bukowski's childhood friend Harold Mortenson, in the 1930s, the two played a statistics-intensive baseball game akin to Strat-O-Matic that involved two dice and two manuals that was marketed under Danny MacFayden's name when he was with the Boston Bees.