Titanium (as "Ti"), the chemical element of atomic number 22.

T.I. (born 1980), an American hip-hop artist.

Ti, an abbreviation for the IEEE prefix tebi which represents 2⁴⁰.

Taiwan independence, a political movement.

Texas Instruments, an American electronics company.

"Ti" (see Solfege), a musical note on the diatonic scale.

Ticino, a canton (federated state) of Switzerland.

The Times Independent, a local newspaper in Moab, Utah.

The Treason of Isengard, a book by Christopher Tolkien

Tyr (as "Ti" from Old Swedish), the deity of Norse mythology.

Thursday Island, an island in the Torres Strait.

Thermal imaging.

"ti" Treasure Island Hotel and Casino in Las Vegas, Nevada.

Transparency International, an international organisation devoted to fighting corruption.

Tī kouka, the New Zealand cabbage tree.

Ti (plant), the plant Cordyline fruticosa.

Acronis True Image, at times referred to as TI - is a disk imaging program.

TI Group, a former British company that owned specialist engineering companies

Time immemorial.

Thermal instability

Tol Air, IATA airline designator.

T'i, "substance" in Chinese.

"Tall Israeli", a slur implicitly directed at Jewish record executive Lyor Cohen by rapper Mos Def in his song "The Rape Over" from The New Danger. "TI" has since been continually used by popular hip-hop blogger Byron "Bol" Crawford to refer to record executives in the hip-hop industry.

Tiger Inn, a Princeton University eating club.

Twilight Imperium, a series of bord games released by Fantasy Flight Games.

Ti, the tumor-inducing plasmid harbored by some Agrobacterium tumefaciens strains or biovars. Also abbreviated pTi.