| Mk | Entry | Card | Episode |
| * | Y-class freighter. | 206.010-a | Fortunate Son. [ENT] |
| * | Y-class freighter. (weapon) | 206.010-b | Fortunate Son. [ENT] |
| Y'Pora. | 104.1L | Begotten, The. [DS9] | |
| Y'Pora. (cabasa noise maker) | 083.17D | Begotten, The. [DS9] | |
| Y'tem." | 034.01I.[E | By Inferno's Light. [DS9] | |
| Y'tem." | 104.1M | By Inferno's Light. [DS9] | |
| * | Y-500-class. | 104.4C | Strange New World. [ENT] |
| ya'nora kor. | 069.164-a | Firstborn. [TNG] | |
| ya'nora kor. | 104.1N | Firstborn. [TNG] | |
| Ya'Seem. | 104.1O | Chase, The. [TNG] | |
| Ya'Vang, I.K.S." | 104.1P | You Are Cordially Invited. [DS9] | |
| Yadalla Prime. | 003.3zMM.[H | Gambit, Part I. [TNG] | |
| Yadalla Prime. | 104.1Q | Gambit, Part I. [TNG] | |
| Yadera II. | 004.15. | Shadowplay. [DS9] | |
| Yadera II. | 004.21-a | Shadowplay. [DS9] | |
| Yadera II. | 104.1R | Shadowplay. [DS9] | |
| Yadera II. (index, a i) (sentient holograms) | 001.070.[O | Shadowplay. [DS9] | |
| Yadera II. (star systems) | 004.01.c | Shadowplay. [DS9] | |
| Yadera Prime. | 104.1S | Shadowplay. [DS9] | |
| Yadera Prime. (Simple living) | 004.15[A | Shadowplay. [DS9] | |
| Yaderans. | 016.1A.[L | Shadowplay. [DS9] | |
| Yaderans. | 104.1T | Shadowplay. [DS9] | |
| Yaderans. (Gamma quadrant) (Races) | 003.5[B.e | Shadowplay. [DS9] | |
| Yadozi Desert. | 104.1U | Man Alone, A. [DS9] | |
| Yak'Talon. | 104.1V | Rocks and Shoals. [DS9] | |
| * | yalasat. | 104.4D | Desert Crossing. [ENT] |
| Yale, Mirasta. | 058.088. | First Contact. [TNG] | |
| Yale, Mirasta. | 104.1W | First Contact. [TNG] | |
| Yale, Mirasta. (A mind for science) | 018.094B[B | First Contact. [TNG] | |
| Yallitians. | 104.1X | Phage. [VGR] | |
| Yalosians. | 104.1Y | Improbable Cause. [DS9] | |
| Yalosians. (ambassador) | 007.18C.[P | Improbable Cause. [DS9] | |
| Yaltar, Gul. | 104.1Z | Image in the Sand. [DS9] | |
| Yaltar, Gul. (guls and operatives) | 050.03.p | Image in the Sand. [DS9] | |
| Yamato, U.S.S." | 031.09B | Where Silence Has Lease. [TNG] | |
| Yamato, U.S.S." | 005.12-b | Contagion. [TNG] | |
| Yamato, U.S.S." | 104.2A | Where Silence Has Lease. [TNG] | |
| yamok sauce. | 070.014-a | Progress. [DS9] | |
| -- | yamok sauce. | 070.118-b | Call to Arms, A. [DS9] |
| yamok sauce. | 104.2B | Progress. [DS9] | |
| Yan-Isleth. | 104.2F | Apocalypse Rising. [DS9] | |
| Yan-Isleth. (Brotherhood of the Sword. SEE: Y) | 082.18Y | Apocalypse Rising. [DS9] | |
| Yanar. | 058.119A | Outrageous Okona, The. [TNG] | |
| Yanar. | 104.2C | Outrageous Okona, The. [TNG] | |
| Yangs. | 018.079.a | Omega Glory, The. [TOS] | |
| Yangs. | 104.2D | Omega Glory, The. [TOS] | |
| Yangs. (index, r) | 001.076.[D.b | Omega Glory, The. [TOS] | |
| Yangs. (Strangely familiar) | 018.079[A.a | Omega Glory, The. [TOS] | |
| Yangs. (Yankees) | 018.079-a1 | Omega Glory, The. [TOS] | |
| Yangtzee Kiang, U.S.S." | 027.13.[G | Emissary, Parts I & II. [DS9] | |
| Yangtzee Kiang, U.S.S." | 104.2E | Emissary, Parts I & II. [DS9] | |
| Yangtzee Kiang, U.S.S." (A threat to the wormhole) | 010.06B[B | Past Prologue. [DS9] | |
| Yar, Ishara. | 044.52. | Legacy. [TNG] | |
| Yar, Ishara. | 104.2G | Legacy. [TNG] | |
| Yar, Ishara. (born) | 007.05APP-a2 | Legacy. [TNG] | |
| Yar, Ishara. (Pseudo sentiment) | 044.52[A | Legacy. [TNG] | |
| Yar, Ishara. (Tasha' sister) | 043.035C[A | Legacy. [TNG] | |
| Yar, Natasha, (alternate). | 024.3.[E | Yesterday's Enterprise. [TNG] | |
| Yar, Natasha, (alternate). | 043.035D | Yesterday's Enterprise. [TNG] | |
| Yar, Natasha, (alternate). | 104.2I | Yesterday's Enterprise. [TNG] | |
| Yar, Natasha, (alternate). (A timeless romance) | 043.116[A.b | Yesterday's Enterprise. [TNG] | |
| Yar, Natasha, (alternate). (Time paradox) | 049.02[A | Redemption, Part II. [TNG] | |
| Yar, Natasha. | 025.34.[H | Encounter at Farpoint, Parts I & II. [TNG] | |
| Yar, Natasha. | 043.035. | Encounter at Farpoint, Parts I & II. [TNG] | |
| Yar, Natasha. | 104.2H | Encounter at Farpoint, Parts I & II. [TNG] | |
| Yar, Natasha. (index) | 001.095. | Encounter at Farpoint, Parts I & II. [TNG] | |
| Yar, Natasha. (background) | 043.035C | ||
| Yar, Natasha. (born) | 007.05APP-a1 | Where No One Has Gone Before. [TNG] | |
| Yar, Natasha. (cat) (index, p) | 001.066.[E | Where No One Has Gone Before. [TNG] | |
| Yar, Natasha. (Deadly arena) | 058.052[A.b | Code of Honor. [TNG] | |
| Yar, Natasha. (Emotional bond) | 018.001A[A.b | Where No One Has Gone Before. [TNG] | |
| Yar, Natasha. (Fallen comrade) | 043.035B[A | Skin of Evil. [TNG] | |
| Yar, Natasha. (Final mission) | 043.035A[A | Skin of Evil. [TNG] | |
| Yar, Natasha. (friends and leisure) | 043.035B | ||
| Yar, Natasha. (Full potential) | 004APP1[B.a | Where No One Has Gone Before. [TNG] | |
| Yar, Natasha. (killed) | 069.062-b | Skin of Evil. [TNG] | |
| Yar, Natasha. (The battle is joined) | 018.098[B.b | Code of Honor. [TNG] | |
| Yar, Natasha. (warrior) | 043.035A | ||
| * | Yarahla." | 104.4E | Breaking the Ice. [ENT] |
| Yareena. | 058.052.a | Code of Honor. [TNG] | |
| Yareena. | 104.2J | Code of Honor. [TNG] | |
| Yareena. (Deadly arena) | 058.052[A.a | Code of Honor. [TNG] | |
| Yareena. (The battle is joined) | 018.098[B.a | Code of Honor. [TNG] | |
| Yareth. | 104.2K | Vortex. [DS9] | |
| Yareth. (Sleeping beauty) | 058.082[A | Vortex. [DS9] | |
| Yarim Fel syndrome. | 104.2L | Ties of Blood and Water. [DS9] | |
| Yarim Fel syndrome. (CNS failure) | 083.17A | Ties of Blood and Water. [DS9] | |
| Yarim Fel syndrome. (triptacederin) | 100.22M.b | Ties of Blood and Water. [DS9] | |
| Yarka. | 010.21A[J | Destiny. [DS9] | |
| Yarka. | 047.14. | Destiny. [DS9] | |
| Yarka. | 104.2M | Destiny. [DS9] | |
| Yarka. | 070.056-a | Destiny. [DS9] | |
| Yarka. (Fall from grace) | 010.03D[B.a | Destiny. [DS9] | |
| Yarka. (Interpretations ignored) | 010.16D[A | Destiny. [DS9] | |
| Yarka. (sabotaging the Bajoran wormhole) | 005.01ii.c | Destiny. [DS9] | |
| Yarnek. | 058.100. | Savage Curtain, The. [TOS] | |
| Yarnek. | 104.2N | Savage Curtain, The. [TOS] | |
| Yarnek. (index, n-h l) | 001.071.[G | Savage Curtain, The. [TOS] | |
| Yaro. | 104.2O | Warlord. [VGR] | |
| Yash-El, night blessing of. | 104.2P | Chase, The. [TNG] | |
| Yassim, Vedek. | 010.21A[K | Rocks and Shoals. [DS9] | |
| Yassim, Vedek. | 070.120-a | Rocks and Shoals. [DS9] | |
| Yassim, Vedek. | 104.2Q | Rocks and Shoals. [DS9] | |
| Yates, Kasidy. | 044.16. | Family Business. [DS9] | |
| Yates, Kasidy. | 104.2R | Family Business. [DS9] | |
| Yates, Kasidy. (Ds9 quarters) | 070.071-a | Indiscretion. [DS9] | |
| Yates, Kasidy. (Team player) | 044.16A[A | Take Me Out to the Holosuite. [DS9] | |
| Yates, Kasidy. (wife of the Emissary) | 044.16A | ||
| * | Yates, William. | 104.4F | Equinox, Part I. [VGR] |
| Yattho. | 104.2S | Before and After. [VGR] | |
| Yeager loop. | 104.2T | First Duty, The. [TNG] | |
| Yeager, U.S.S." | 031.27. | Star Trek: First Contact. | |
| Yeager, U.S.S." | 099.01E.b | Star Trek: First Contact. | |
| Yeager, U.S.S." | 104.2U | Star Trek: First Contact. | |
| Year of Hell, Part I. (index, a r) | 001.096.[P.a | Year of Hell, Part I. [VGR] | |
| Year of Hell, Part I. (Voyager, U.S.S.") (days 1-73) | 029.30.[A-I | Year of Hell, Part I. [VGR] | |
| Year of Hell, Part II. (index, a r) | 001.096.[P.b | Year of Hell, Part II. [VGR] | |
| Year of Hell, Part II. (Voyager, U.S.S.") (days 133-257) | 029.30.[J-P | Year of Hell, Part II. [VGR] | |
| * | Yediq, Warden. | 058.085. | Repentance. [VGR] |
| * | Yediq, Warden. | 104.4G.a | Repentance. [VGR] |
| * | Yediq, Warden. (index, c) | 001.068.[M | Repentance. [VGR] |
| * | Yeggie. | 104.4H | Inside Man. [VGR] |
| * | Yegi. | 014.13.b | Inside Man. [VGR] |
| * | Yegi. (Spreading the wealth) | 014.13[B.b | Inside Man. [VGR] |
| yelg melon. | 104.2X | Children of Time. [DS9] | |
| Yelgrun. | 058.002. | Magnificent Ferengi, The. [DS9] | |
| Yelgrun. | 104.2Y | Magnificent Ferengi, The. [DS9] | |
| Yellow Alert. | 059.23.a | ||
| / | Yellow Alert. | 104.2Z | |
| Yellow Alert. (Starfleet alerts and emergency procedures) | 019.12.a | ||
| Yellowstone, U.S.S." (NCC-70073) | 104.2AA | Melora. [DS9] | |
| Yellowstone, U.S.S." (NX-74751) | 104.2AB | Non Sequitur. [VGR] | |
| Yeln. | 104.3A | Second Skin. [DS9] | |
| * | Yerid. | 104.5A | Workforce, Part II. [VGR] |
| Yeto. | 104.3B | Invasive Procedures. [DS9] | |
| * | Yifay. | 058.096.a | Child's Play. [VGR] |
| * | Yifay. | 104.5B | Child's Play. [VGR] |
| Yigrish cream pie. | 104.3C | Distant Voices. [DS9] | |
| yih-Ghom-HAH. | 104.3D | Sons and Daughters. [DS9] | |
| Yint. | 104.3E | Honor Among Thieves. [DS9] | |
| Yiri, General. | 104.3G | Profit and Loss. [DS9] | |
| Yiri, General. (Trelonium government) | 100.26W | Profit and Loss. [DS9] | |
| * | Yivel. | 104.5C | Child's Play. [VGR] |
| ylntagh. | 104.3F | Redemption, Part I. [TNG] | |
| Yndar. | 104.3H | Apocalypse Rising. [DS9] | |
| Yog. | 104.3I | Firstborn. [TNG] | |
| * | Yolja River. | 104.3J | Penumbra. [DS9] |
| yominium sulfide. | 104.3K | Star Trek IV: The Voyage Home. | |
| Yonada." | 040.003. | For the World Is Hollow and I Have Touched the Sky. [TOS] | |
| Yonada." | 104.3L | For the World Is Hollow and I Have Touched the Sky. [TOS] | |
| Yonada." (Hollow world) | 018.065[A | For the World Is Hollow and I Have Touched the Sky. [TOS] | |
| Yonada." (Interior civilizations) | 011APP1[A.a | For the World Is Hollow and I Have Touched the Sky. [TOS] | |
| Yonada." (non-Federation starships) | 033.1.s | For the World Is Hollow and I Have Touched the Sky. [TOS] | |
| Yonada." (Rocky exterior) | 040.003[A | For the World Is Hollow and I Have Touched the Sky. [TOS] | |
| Yonada." (unconventional non-Federation ships) | 040APP3.g | For the World Is Hollow and I Have Touched the Sky. [TOS] | |
| * | Yontasa Expanse. | 104.5D | Imperfection. [VGR] |
| Yorktown, U.S.S." (NCC-?????) | 104.3O | Flashback. [VGR] | |
| Yorktown, U.S.S." (NCC-1717) | 031.04. | Obsession. [TOS] | |
| Yorktown, U.S.S." (NCC-1717) | 075.1-a | Star Trek IV: The Voyage Home. | |
| Yorktown, U.S.S." (NCC-1717) | 031.04E.[H | Obsession. [TOS] | |
| Yorktown, U.S.S." (NCC-1717) | 104.3P | Obsession. [TOS] | |
| Yorktown, U.S.S." (NCC-61137) | 104.3Q | All Good Things... [TNG] | |
| Yoruba mask. | 104.3R | Search, The, Part I. [DS9] | |
| * | Yosa. | 029.43D.[T | Repression. [VGR] |
| * | Yosa. | 104.5E | Repression. [VGR] |
| Yosemite National Park. | 007.03Ai | Star Trek V: The Final Frontier. | |
| Yosemite National Park. (bears) | 007.03Ai-c | Star Trek V: The Final Frontier. | |
| Yosemite National Park. (Glacier Point) | 007.03Ai-a | Star Trek V: The Final Frontier. | |
| Yosemite National Park. (Horsetail Fall) | 007.03Ai-b | Star Trek V: The Final Frontier. | |
| Yosemite National Park. (The green, green grass of home) | 007.03A[A.b | Star Trek V: The Final Frontier. | |
| Yosemite, U.S.S." | 031.07A.[I | Realm of Fear. [TNG] | |
| Yosemite, U.S.S." | 104.3S | Realm of Fear. [TNG] | |
| Yoshi. (Y. SEE: O'Brien, Kirayoshi) | 104.3T | Ties of Blood and Water. [DS9] | |
| Yoshimitsu computer. | 104.3U | Up the Long Ladder. [TNG] | |
| * | Yost, Supervisor. | 004.26-b | Gravity. [VGR] |
| * | Yost, Supervisor. | 104.3V | Gravity. [VGR] |
| * | Yost, Supervisor. (Sealing a sinkhole) | 005.28[B | Gravity. [VGR] |
| * | Yost, Supervisor. (vessel) | 040APP2N.[D | Gravity. [VGR] |
| * | Young, Ensign. | 029.43D.[S | Imperfection. [VGR] |
| \ | Young. | 104.3W | In the Flesh. [VGR] |
| Yranac. | 104.3X | Gambit, Part I. [TNG] | |
| Yridian brandy. | 104.3Z | Sword of Kahless, The. [DS9] | |
| Yridian brandy. (A matter of taste) | 018.184[B.b | Sword of Kahless, The. [DS9] | |
| Yridian freighter. | 104.3AA | Firstborn. [TNG] | |
| Yridian freighter. (Freighters) | 040APP1[AU | Firstborn. [TNG] | |
| Yridian tea. | 104.3AB | Eye of the Beholder. [TNG] | |
| Yridian tea. (A matter of taste) | 018.184[B.a | Eye of the Beholder. [TNG] | |
| Yridian yak. | 104.3AC | Accession. [DS9] | |
| Yridians. | 018.184. | Chase, The. [TNG] | |
| Yridians. | 104.3Y | Chase, The. [TNG] | |
| Yridians. (destroyer) | 018.184-a | Chase, The. [TNG] | |
| yridium bicantizine. | 104.3AD | Statistical Probabilities. [DS9] | |
| yridium bicantizine. (trinucleic fungus) | 100.22B | Statistical Probabilities. [DS9] | |
| * | yrott. | 104.5F | Desert Crossing. [ENT] |
| \ | Yuen. | 104.3AE | Blaze of Glory. [DS9] |
| Yukon, U.S.S." | 027.13.[H | Sons of Mogh. [DS9] | |
| Yukon, U.S.S." | 104.3AF | Sons of Mogh. [DS9] | |
| * | Yun. | 104.5G | Friendship One. [VGR] |
| Yuta. | 058.033. | Vengeance Factor, The. [TNG] | |
| Yuta. | 069.056-a | Vengeance Factor, The. [TNG] | |
| Yuta. | 104.3AG | Vengeance Factor, The. [TNG] | |
| Yuta. (index, c o) | 001.087.[G | Vengeance Factor, The. [TNG] | |
| Yuta. (index, g e) | 001.075.[J | Vengeance Factor, The. [TNG] | |
| Yuta. (Revenge from the past) | 018.066A[B | Vengeance Factor, The. [TNG] | |
| Yuta. (Shocking discovery) | 058.033[A | Vengeance Factor, The. [TNG] | |
| Yuta. (victims) | 018.066A-a | Vengeance Factor, The. [TNG] | |
| Yutan. | 104.3AH | Private Little War, A. [TOS] |