TMI

TMI can be
Organizations
 TMI Associates, a Japanese law firm
 TMI Episcopal, formerly Texas Military Institute, a preparatory school 
 Taiwan Music Institute, a musical institute in Taiwan

 Three Mile Island Nuclear Generating Station, a nuclear power station in Pennsylvania, USA
 Time Module (TMI), a member of the Seiko Group, manufacturer of watch movements
 Toastmasters International, an international public speaking organization

 The Monroe Institute, a nonprofit education and research organization

Science
 Transmarginal inhibition, a mental response to extreme stresses or pain
 Trimethylindium, part of chemistry 
 Trans-Mars injection, a propulsive maneuver used to set a spacecraft on a trajectory which will cause it to arrive to Mars

Other uses
 TMI, abbreviation for "Too much information", indicating information overload or excessively personal information

 Ton-mile or tmi, a unit of freight transportation quantity
 Tumlingtar Airport, an airport serving Tumlingtar, a city in Nepal
 "TMI" a song by Joan Jett and the Blackhearts from the 2013 album Unvarnished