Trefolg was a Federation planet located near the Romulan Neutral Zone.

Trefolg was one of the Federation's closest colonies to the Neutral Zone. It was equipped with high-powered subspace radio equipment to account for its distance from Federation support. Trefolg's governor in 2269 was Lerak Kepac, around which time the colony was suffering from a deficiency in refined, alloyed metal.

Also in 2269, members of the United Expansionist Party acquired a starship on Trefolg and planned an incursion into the Neutral Zone to spark a conflict between the United Federation of Planets and the Romulan Star Empire. The conspirators were captured by colonial authorities and transferred to Starfleet custody aboard the USS Enterprise. (TOS novel: The Trellisane Confrontation)

planets visited by the USS Enterprise (NCC-1701) during Captain Kirk's initial five-year mission (2265-2270)
various Aprilia IIICaporyGarrusTriangularis III
2265 EarthDraxis IITallyGamma Alpha VPollux IIStarbase 8 planetSector Vega 6 planetM-155Archernar IVDimorusMandylion VTendar IVMestikoAlpha Ortelina VIIArronus VIIAldebaran IIIDelta Vega IStarbase 12VelluriusEarthEmpyreaGlobular planetNorusJunkyard planetPalnak's planetSantarNova XIIIZeltokKorakTraveler's homeworldDukarOrthooAlgenib II
2266 Crucial-3VultraRobots' planetAngomaMantis planetNuofoStaiVrexBalant planetZargotColtacRigel XIIAlfa 177M-113Psi 2000Tlaoli IVSkurSelkyeTaragonAlpha 332Ynobe IIEcnalRayloNorigaAlpha Proxima IIArgylusOminnusEarthK-GSeggorForniaAngiraBeta IINeesanKujalLunaBwujaFayoHerculaEarthKibo/NdoraNrakaAlpha 23-COordonMobitaJodarrQuodarZartaFloe IMetamorphaInicrustMortiTerrellian IIVoodoo planetRiza homeworldMila XaKrugar III remnantQuaraxusArimaMazdaNumero UnoBeta CarinaeExo III1324-IV7348-IITantalus VMiri's homeworldPlanet QBenecia
2267 Taurus IIMakus IIIXimega IIHydra Epsilon IIIPerseus Arm planetoidYkoTenkaraSalvumGrotusVaranu planetYkoTalos IVTektonRifas-LAmusement Park planetHeitius VIICentaurus VFomalhaut VEmben IIICynur IVTyrtaeus IIGothosBeta VITheta VIIRamedes IIICestus IIIAlvaLazarus's planetGalaxy Zekbran planetCygnet XIVEarthCanaraBeta IIIDraqqanaEminiar VIICeti Alpha VGamma 400VartaxDak-AlphaTimshelOmicron Ceti IIIJanus VI7348-IIChandra IVOrganiaAngrenaYkoEarth Colony IIGatewayEarthDenevaJanvarZentarZettin • "the Frontier" • ModalaLadoGamma XaridianElsinor H-25Starbase 10Beta Mariotia IIIVega IIITondusTekkorCarnakPyris VIIEarthPentam VGamma Canaris NVandros VIINukoleeStyraLurotaOorego IVGiant Brain asteroidOtari IIGatewayIsis IIINot EdenMaaba S'JaCapella IVPollux IVVulcanMestikoNadorTactis IIBeta Nirobi IIPhygma IVOutpost Omega-70Tau Gamma IVM-370Argelius IIMerope IVMalurEulusDonico IIGamma Trianguli VIMasabaLekythosTyrtaeus IIShroud IVHalkaIxtoldeGamma Hydra IVCalydonBelmara IVTuran Tot Narut's planetGamma Canaris NTaunusPlanet 656Beton IIIKwettirSklurrKarrGraktanTharkMorkolPlixesAndriusMuddEarthAneher IIWezonvuNalaingMagna RomaBavaryaNeolithiaMythraRimilliaBabelGamma Canaris NTNC 65813VulcanNisusCertaxNarnel's WorldNGC 667Neural
2268 Fornax IIGamma IITriskelionRudimonArgus XTycho IVCentaurusUsildeTheta VIISigni BetaTautee systemVulcanBeta Canzandia IIIMevinnaSigma Iotia IIXanviaXoxxaInquisitor's planetBeta ReticuliDelta VegaNalogen IVDelta VegaDelta Canaris IVAlnath IIAmmdonArretEkosEeiauoSivaoKahlessOmega IVEarthTheta Kiokis IIElasTroyiusElethiaAlsandKosTau Delta IXAmerindStarbase 14 planetAndru 4/6Tranquility VIIMinos VEarthExo IIIT'nufoMinos VEando 375Wrigley's Pleasure PlanetExo IIITortuga VITaos IVTriacusMarcos XIIWokkle IIICawley IVMakon IIIKalaLowariaDreamers' planetSigma Draconis VIMoauvPomplanceRibol IIMarpapluDireidiMedusaElcidar Beta IIIMinara IIOctavius IVBeta CabriniPegasus IVCareta VBeta XII-APlatoniusIzellEarthScalosM-317Beta Aurigae IIISanoora host planetRhinegeltKalandan outpostBrellian IVPrastorDistrelTttnicktttnorAriannusCheronElba IISanctuaryGideonKolya
2269 Memory AlphaMerak IIArdanaPollux VAvalonBalkos IIINova Atar IIITarnak IIMeta IVVesbiusJanus VIPollux IILeora IVBeta Niobe IIIMygdalus IIIWaasertlaCentaurusRaga's PlanetEdenTheta Tau VHolberg 917GLothorTau Beta IVExcalbiaSarpeidonCamus IIDuwamishEphrata IVSigma Niobe IIGatewayKrasni's FollyVestalanMaltos IVOrganiaKyrosNestaAnomalyAcademyYkoArachnaeBabelEpsilon Delta IVHeartlandMemory PrimeTalin IVWeb of WorldsSyhaar PrimeGatewayMantillesValeriaTaurus IIKinshasaAmusement Park planetMotherlodeMegas-TuTerratinSherman's PlanetVerdaniaThe StrandAarak IIIPhi XIUr homeworldVidenGobi IIIPacificaGralafiLoren VArgoWaycrossDengella IIPerryDelta Gamma IVDetente ITrefolgLloyd Zeta-9Sigma Iotia IIHesperides II'QosCirce VTrellisaneBeta CastelliHeloxBoaco VIJuram VVancadiaChyrellkaVeletus VPatria IPelos
2270 Janus VIPhylos IIVedala asteroidDramiaDramia IIArretLactra VIIBoqu IIDelta Theta IIIPandroBriamosBelarius IVVelat Nol/R-836 IIGelladorn/R-775 IDT-262Belarius IVLotora IIICenotaphVehtora IVN'caiMuldoonCoridan IIIAkladiMuddKubanSaraiStarbase 7 planetStella Mudd's planetMuddTaygeta VOkeanosBeta Omicron Delta IIIYoondriGatewayZeta GibraltarAndrosYusubArtemys 314KwettirPolymax VIIIHollow PlanetEarth (alternate)GatewaySycoraxBira IIINjuraOmne's planetVoranRazarMercanAleriadAritaniYalboVulcanUnnamed Hoshan planetsTanisAragosAleph PrimeAleph IIIAntos IVTakoi homeworldEarthDenebiaVeneu IIKlondike VIIsitra ZeroPelosArchernar IVTalos IVPillagra/R-855EarthStarbase 12Tomarii
Community content is available under CC-BY-SA unless otherwise noted.