Daniel Ralph Iassogna (born May 3, 1969 in Bridgeport, CT) is an American umpire in Major League Baseball. He joined the major league staff in 1999.

Iassogna began his pro umpiring career straight out of college in the 1992 New York-Penn League. After two years there, he worked in the 1994 South Atlantic League, 1995 Carolina League, 1996-1997 Texas League and 1998-2003 International League.

He made it to the majors on August 20, 1999, and worked games in both the American League and National league that season, helping out when the umpires union put forward its ill-fated mass resignation strategy late that year. With the openings created by the resignations, he became a full-time big league umpire in 2000.

On August 13th 2002 at Arlington, Texas in a game between the Texas Rangers & the Chicago White Sox, Iassongna was part of a history making umpire crew. The umpiring crew was made up of the same ethnic background, all Italian / Americans. Iassogna was on the line at third base, Tony Randazzo at second base, Larry Poncino on the line at first base & Ed Rapuano was behind the plate.

Ed worked both of Justin Verlander's no-hitters,

Dan worked the 2009 World Baseball Classic and 2011 All-Star Game, and worked his first World Series in 2012. He returned to international umpiring by working the 2017 World Baseball Classic. He was promoted to crew chief in 2020. While some find Dan confrontational, he also is a "frequent blood platelet donor, [and] proudly works with the Chicago Fire Department in support of the ‘Bucks for the Burn Camp,’ which helps children that were burned in fires."

(excerpted from Centerfield Maz, Baseball Almanac, BR Bullpen & Wikipedia)