| Firmi | Firmiana | Firmiana chinensis |
| Firmiana platanifolia | Firmiana platanifolia var. tomentosa | Firmiana simplex |
| Firmiano de Morais Pinto | Firmico Materno | Firmicus |
| Firmicus (cráter) | Firmicus abnormis | Firmicus arushae |
| Firmicus aurantipes | Firmicus biguttatus | Firmicus bimaculatus |
| Firmicus bipunctatus | Firmicus bivittatus | Firmicus bragantinus |
| Firmicus campestratus | Firmicus dewitzi | Firmicus duriusculus |
| Firmicus haywoodae | Firmicus insularis | Firmicus lentiginosus |
| Firmicus paecilipes | Firmicus strandi | Firmicus werneri |
| Firmicute | Firmicutes | Firmiliano de Cesarea |
| Firmin | Firmin (novela) | Firmin Abauzit |
| Firmin Bouisset | Firmin Didot | Firmin Gémier |
| Firmin Gemier | Firmin Girard | Firmin Lambot |
| Firmin Massot | Firmin Mubele | Firmin Ndombe Mubele |
| Firmin Ngrebada | Firmin Zokou | Firmin-Girard |
| Firmina de Amelia | Firmine Richard | Firmino Alves |
| Firmino Baptista | Firmino Filho | Firmino Monteiro |
| Firminus Caron | Firminy | Firmissimam constantiam |
| Firmistáns | Firmo | Firmo (Italia) |
| Firmo Únzaga | Firmo II | Firmum |
| Firmus Piett | Firmware | Firn |
| FIROM | Firoozeh Dumas | Firozabad |
| Firozkoh | Firozpur | Firpo |
| Firpo Segura | Firrel | Firrerre |
| FIRS | Firs Botanical Grounds | Firsdown |
| Firsov (cráter) | FIRST | First |
| First (álbum) | First (canción) | First (revista) |
| First Aid Kit | First Aid Kit (banda) | First Aiders |
| First Air | First Alert | First Among Equals |
| First and Last and Always | First And Last And Always | First Arthur County Courthouse and Jail |
| First Assessment (Minnesota) | First Automobile Works | First Avenue (Manhattan) |
| First Band on the Moon | First band on the moon | First Baptist Church (Detroit, Michigan) |
| First Baptist Church (Hoboken, New Jersey) | First Baptist Church (Lansing, Michigan) | First Baptist Church of Glenarden |
| First Battle of Cannanore | First Blood | First Blood (novela) |
| First Blood Last Cuts | First Blood Match | First Born |
| First Boston | First Canadian Centre | First Canadian Place |
| First Certificate | First certificate in english | First Certificate in English |
| First Choice | First Choice Airways | First Christian Church (Columbus, Indiana) |
| First Church of Christ, Scientist (Berkeley, California) | First Citizens Cup | First City Tower |
| First Class | First Class 10 | First Class 8 |
| First Coconut Grove School | First Come First Served | First come first served |
| First Come, First Served | First come, first served | First Comes the Night |
| First Comics | First comics | First Congregational Church of Detroit |
| First Cow | First Date | First Date (canción) |
| First Date (cancion) | First Dates | First Dates Café |
| First Dates: Crucero | First Daughter | First Day |
| First day of my life | First Day of my Life | First Day Of My Life |
| First Day of My Life | First Day of My Life (canción) | First Day of My Life (cancion) |
| First day of my life (single) | First Daze Here (The Vintage Collection) | First Demo Tape |
| First Ditch Effort | First Down | First Down (Prison Break) |
| First Dream | First Encounter Assault Recon | First Encounter Tour 1996 |
| First Federal Building | First Financial Bank (Ohio) | First Financial Center |
| First Fleet | First Folio | First German Reformed Church |
| First Glance | First Glance / Harder... Faster | First Group |
| First Hand | First Harvest The Best of Alphaville 1984 1992 | First Harvest The Best of Alphaville 1984-1992 |
| First Harvest: The Best of Alphaville 1984 1992 | First Harvest: The Best of Alphaville 1984-1992 | First Hawaiian Center |
| First Hill Streetcar | First Horizon Bank | First Houses |
| First Impact | First Impressions (Angel) | First Impressions of Earth |
| First impressions of earth | First in first out | First In First Out |
| First In Last Out | First in last out | First in never out |
| First In Never Out | First in, first out | First In, First Out |
| First In, Last Out | First in, last out | First in, never out |
| First In, Never Out | First Inner Mongolia Machinery Factory | First International Computer |
| First Interstate Center | First Issue | First Japan Tour Wake Up: Open Your Eyes |
| First kaleidscope ~Kimi no Uchi ni Tsuku Made Zutto Hashitte Yuku~ | First Kid | First Kid, El hijo del presidente |
| First Kiss | First Kiss (serie de televisión) | First Knight |
| First Lady of Israel | First Landing Party of the Founders of Newark | FIRST Lego League Challenge |
| First Line Films | First Live Recordings | First Look Media |
| First Lord of the Admiralty | First Lord of the Treasury | First Love |
| First Love (álbum) | First Love (canción de Jennifer Lopez) | First Love (canción de Lost Kings) |
| First Love (EP) | First Love (Hikaru Utada) | First Love (Utada Hikaru) |
| First Love Sisters | First Majestic Silver | First Man |
| First Man (canción) | First Market Tower | First meeting of the Internet Governance Forum |
| First Mesa | First Mesa (Arizona) | First Minister |
| First Mortgage Company Building | First Nation Airways | First National |
| First National Bank and Trust Building (Lima, Ohio) | First National Bank Building | First National Bank Building (Albuquerque) |
| First National Bank Building (Ann Arbor) | First National Bank Building (Ann Arbor, Michigan) | First National Bank Building (Hartford) |
| First National Bank Building (Hartford, Connecticut) | First National Bank Building (Pittsburgh) | First National Bank Building (Portland) |
| First National Bank Building (Portland, Oregon) | First National Bank Building (Saint Paul) | First National Bank Building (Saint Paul, Minnesota) |
| First National Bank of Commerce Building | First National Bank of Rock River | First National Bank Stadium |
| First National Bank Tower | First National Building | First National City Bank |
| First National City Bank of New York | First National Pictures | First National State Bank Building |
| First Nations | First nations | First Nations Experience |
| First Niagara Center | First of His Name | First of May (librería) |
| First of May (Librería) | First of the Gang to Die | First of the Year (Equinox) |
| First Of The Year (Equinox) | First Orbit | First party |
| First past the post | First Person Shooter | First person shooter |
| First Place Tower | First Police Precinct Station House | First Presbyterian Church (Cass City, Michigan) |
| First Presbyterian Church (Coldwater, Michigan) | First Presbyterian Church (Hartford City, Indiana) | First Quantum Minerals |
| First Racing | FIRST Racing | First Rand |
| First Rand Group | First Rand Limited | First Reformed |
| First Republic Bank | FIRST Res-Q | First Reserve Corporation |
| First Responder Bowl | FIRST Robótica | FIRST Robotica |
| FIRST Robotics Competition | First Rose of Spring | First Roumanian-American congregation |
| First Round Knock Out | First school | First Sea Lord |
| First Security Bank Building | First Sessions | First Seven Kisses |
| First Shearith Israel Graveyard | First Solar | First soundscope ~Mizu no nai Hareta Umi e~ |
| First Squad | First Squad: The Moment of Truth | First Sting |
| First Strike for Spiritual Renewance | First strike for spiritual renewance | First Strike Still Deadly |
| First Sunday | First Tactical Air Force | First Take |
