https://en.wiktionary.org/wiki/hello#Translations
Abkhaz: бзиа збаша (bzia zbaša), мыш бзи (məš bzi), (to a man) бзиара убааит (bziara ubaaiṭ), (to a woman) бзиара ббааит (bziara bbaaiṭ), (to more than one person) бзиара жәбааит pl (bziara ž°baaiṭ)
Afrikaans: hallo (af), goeiedag
Ainu: イランカラㇷ゚テ (irankarapte)
Albanian: tungjatjeta (sq), tung (informal), ç'kemi m or f

    Arbëreshë Albanian: falem (sq)

Alemannic German: sälü, hoi, hello
Aleut: aang, draas
Ambonese Malay: wai
American Sign Language: B@Sfhead-PalmForward B@FromSfhead-PalmForward
Amharic: ሰላም (sälam)
Apache:

    Jicarilla: dá nzhǫ́
    Western Apache: dagotʼee, daʼanzho, yaʼateh

Arabic: السَّلَامُ عَلَيْكُمْ‎ (ar) (as-salāmu ʿalaykum), سَلَام‎ (ar) (salām), مَرْحَبًا‎ (ar) (marḥaban), أَهْلًا‎ (ar) (ʾahlan)

    Egyptian Arabic: اهلاً‎ (ahlan)
    Iraqi Arabic: هلو‎ (helaww)

Archi: салам алейкум (salam alejkum), варчӀами (warčʼami)
Armenian: բարև (hy) (barew), ողջույն (hy) (ołǰuyn)
Assamese: নমস্কাৰ (nomoskar) (very formal), আচ্চেলামো আলাইকোম (asselamü alaiküm) (formal, used among Muslims), হেল’ (helö)
Assyrian Neo-Aramaic: ܫܠܵܡܵܐ‎ (šlama), (to a man) ܫܠܵܡܵܐ ܥܲܠܘܼܟ݂‎ (šlama ʿāloḳ), (to a woman) ܫܠܵܡܵܐ ܥܲܠܵܟ݂ܝ‎ (šlama ʿālaḳ), (to more than one person) ܫܠܵܡܵܐ ܥܲܠܵܘܟ݂ܘܿܢ‎ (šlama ʿāloḳon)
Asturian: hola (ast)
Azerbaijani: salam (az), səlam (South Azerbaijani), hər vaxtınız xeyir olsun, hər vaxtınız xeyir
Bashkir: сәләм (säläm)
Basque: kaixo (eu)
Bats: please add this translation if you can
Bavarian: servus, grias di, pfiati (Timau)
Belarusian: віта́ю (vitáju), здаро́ў (zdaróŭ) (colloquial), до́бры дзень (dóbry dzjenʹ) (good day)
Bengali: নমস্কার (bn) (nômôśkar), আসসালামুআলাইকুম (aśśalamualaikum), সালাম (śalam), হ্যালো (hjalo)
Bhojpuri: प्रणाम (praṇām)
Bouyei: mengz ndil
Bulgarian: здра́сти (bg) (zdrásti) (familiar), здраве́й (bg) sg (zdravéj) (familiar), здраве́йте (bg) pl (zdravéjte) (formal)
Burmese: မင်္ဂလာပါ (my) (mangga.lapa) , ဟဲလို (my) (hai:lui) (colloquial)
Catalan: hola (ca)
Cayuga: sgę́:nǫʔ
Central Atlas Tamazight: ⴰⵣⵓⵍ (azul)
Chamorro: håfa adai
Chechen: маршалла ду хьоьга (maršalla du ḥöga) (to one person), маршалла ду шуьга (maršalla du šüga) (to a group of people), ассаламу ӏалайкум (assalamu ʿalajkum)
Cherokee: ᎣᏏᏲ (chr) (osiyo)
Chichewa: moni
Chickasaw: chokma
Chinese:

    Cantonese: 你好 (nei5 hou2), 哈佬 (haa1 lou2)
    Dungan: ни хо (ni ho), сэляму (seli͡amu), хома (homa)
    Hakka: 你好 (ngì-hó)
    Mandarin: 你好 (zh) (nǐ hǎo), 您好 (zh) (nín hǎo) (polite), 你們好, 你们好 (nǐmen hǎo) (to a group of people), 好 (zh) (hǎo) (following an address form or name), 嗨 (zh) (hāi), 哈囉 (zh), 哈啰 (zh) (hāluó)
    Min Dong: 汝好 (nṳ̄ hō̤)
    Min Nan: 汝好 (lí hó)
    Xiang: please add this translation if you can
    Wu: 儂好, 侬好 (non hau)

Choctaw: halito
Chukchi: еттык (ettyk) (formal), ети (eti) (informal), етти (etti) (informal)
Coptic: ⲛⲟϥⲣⲓ (nofri)
Cornish: dydh da
Corsican: bonghjornu
Cree:

    Plains Cree: tânisi 

Czech: ahoj (cs), nazdar (cs) (informal), servus (cs) (informal), dobrý den (cs) (formal)
Danish: hej (da), dav (da), god dag (formal), hallo (da)
Dhivehi: އައްސަލާމު ޢަލައިކުމް‎ (assalāmu ʿalaikum̊)
Dutch: hallo (nl), hoi (nl), hai (nl), hé (nl), dag (nl) (informal), goeiedag (nl), goededag (nl), goedendag (nl), goeiendag (nl) (formal)
Esperanto: saluton (eo)
Estonian: tere (et), hei (et)
Faroese: hey, halló
Fijian: bula (fj)
Finnish: terve (fi), moi (fi), hei (fi), moikka (fi)
French: bonjour (fr), salut (fr) (informal), coucou (fr)(informal), cocorico (fr)
Friulian: mandi
Galician: ola (gl), oula, ouga
Georgian: გამარჯობა (ka) (gamarǯoba), ჰეი (hei)
German: hallo (de), guten Tag (de), servus (de), moin (de), grüß Gott (de) (Southern German, Austria)

    Alemannic German: grüezi

Gilbertese: mauri
Gothic: 𐌷𐌰𐌹𐌻𐍃 (hails), 𐌷𐌰𐌹𐌻𐌰 (haila)
Greek: γεια (el) (geia), γεια σου sg (geia sou), γεια σας pl (geia sas), χαίρετε (el) (chaírete)

    Ancient: χαῖρε sg (khaîre), χαίρετε pl (khaírete), χαῖρε καί ὑγίαινε sg (khaîre kaí hugíaine)

Greenlandic: aluu (kl)
Guaraní: maitei (gn)
Gujarati: નમસ્તે (namaste), નમસ્કાર (namaskār)
Haitian Creole: bonjou
Hausa: sannu
Hawaiian: aloha
Hebrew: שָׁלוֹם‎ (he) (shalóm), שָׁלוֹם עָלֵיכֶם‎ (he) (shalóm 'aleikhém)
Hindi: नमस्ते (hi) (namaste), नमस्कार (hi) (namaskār), सलाम (hi) (salām) (used by Muslims), सत श्री अकाल (sat śrī akāl) (Sikh, hello/goodbye), हेलो (hi) (helo), हलो (halo), सत्य (hi) (satya), आदाब (hi) (ādāb)
Hmong:
    Green Hmong: nyob zoo
    White Hmong: nyob zoo
Hungarian: szia (hu), sziasztok (hu) pl (informal), szervusz (hu), szervusztok pl (somewhat formal), heló (hu), helló (hu) (informal), jó napot (hu), jó napot kívánok (hu) (formal), üdvözlöm
Icelandic: halló (is), hæ (is), góðan dag (is), góðan daginn (is)
Ido: hola (io)
Igbo: kèdu
Indonesian: hai (id), salam (id)
Interlingua: bon die, salute (ia)
Irish: Dia dhuit (formal, singular), Dia dhaoibh (formal, plural), Dia's Muire dhuit (formal, singular, response), Dia's Muire dhaoibh (formal, plural, response)
Isan: please add this translation if you can
Italian: ciao (it), salve (it), buongiorno (it), saluti (it) m pl
Iu Mien: yiem longx nyei
Jamaican Creole: ello, wah gwaan
Japanese: おはよう (ja) (ohayō) (morning), こんにちは (ja) (konnichi wa) (daytime), こんばんは (ja) (konban wa) (evening)
Javanese: halo
Jeju: 반갑수다 (ban-gapsuda), 펜안ᄒᆞ우꽈 (pen-anhawukkwa), 펜안 (pen-an)
Judeo-Tat: шолум (şolum)
Kabardian: уузыншэм (wwzənšăm)
Kabyle: azul
Kalmyk: мендвт (mendvt), менд (mend) (informal)
Kannada: ತುಳಿಲು (kn) (tuḷilu), ನಮಸ್ಕಾರ (kn) (namaskāra)
Karachay-Balkar: кюнюгюз ашхы болсун (künügüz aşxı bolsun), ассаламу алейкум (assalamu aleykum)
Karelian: terveh, hei
Kazakh: сәлем (kk) (sälem) (informal), сәлеметсіздер (sälemetsızder) (formal)
Khmer: ជំរាបសួរ (cumriəp suə), សួស្តី (suəsdəy)
Khün: please add this translation if you can
Kinyarwanda: muraho
Korean: 안녕하십니까 (annyeonghasimnikka) (formal), 안녕하세요 (ko) (annyeonghaseyo) (neutrally formal), 안녕(安寧) (ko) (annyeong) (informal)
Krio: kushɛ
Kurdish:

    Northern Kurdish: merheba (ku), silav (ku), selam (ku)

Kyrgyz: саламатсыздарбы (salamatsızdarbı), салам (ky) (salam)
Ladino: shalom, bonjur, buenos diyas
Lak: салам (salam)
Lakota: háu
Lao: ສະບາຍດີ (sa bāi dī)
Latin: salvē (la) sg, salvēte (la) pl; avē (la) sg, avēte pl
Latvian: sveiki (informal to more than one person or people of indeterminate gender), sveiks (to a man), sveika (to a woman), čau (informal)
Laz: გეგაჯგინას (gegaǯginas)
Lezgi: салам (salam)
Lithuanian: labas (lt), sveikas (lt) (informal), sveiki (lt) (formal)
Livonian: tēriņtš
Luo: msawa
Lü: ᦍᦲᧃᦡᦲ (yiinḋii)
Luxembourgish: hallo
Macedonian: здраво (zdravo)
Malagasy: manao ahoana? (mg), salama (mg) (Tsimihety)
Malay: helo (ms), apa khabar (ms), salam (ms)
Malayalam: ഹലോ (halō), നമസ്തേ (ml) (namastē), നമസ്കാരം (ml) (namaskāraṃ)
Maltese: bonġu (mt) (before noon), bonswa (after noon), nsellimlek (formal one to one person), nsellmilkom (formal one to more than one person), nsellmulek (formal more than one person to one person), nsellmulkom (formal more than one person to more than one persons)
Manchu: ᠰᠠᡳᠶᡡᠨ (saiyūn)
Maori: kia ora (mi) (informal), tēnā koe (formal to one person), tēnā kōrua (formal to two people), tēnā koutou (formal to three or more people)
Mapudungun: mari mari
Maranungku: yo
Marathi: नमस्कार (mr) (namaskār)
Michif: tánishi, boñjour
Mingrelian: გომორძგუა (gomorʒgua)
Mohawk: sekoh
Mongolian:

    Cyrillic: сайн уу? (mn) (sayn uu?) (informal), сайн байна уу? (mn) (sayn bayna uu?)

Mopan Maya: dʼyoos
Nahuatl: niltze (nah), panoltih
Navajo: yáʼátʼééh
Neapolitan: uè
Nepali: नमस्ते (ne) (namaste), नमस्कार (ne) (namaskār)
Norman: baon-n-jour (Guernsey), banjour (Guernsey), boujouo (continental Normandy), bouônjour (Jersey), bwõju (Sark)
Northern Thai: สบายดีก่อ
Norwegian:

    Bokmål: hallo (no), hei (no), god dag (no) (formal), halla (no) (informal), heisann

Ojibwe: boozhoo
Okinawan: はいさい m (haisai), はいたい f (haitai), はい n (hai)
Old English: wes hāl
Oriya: ନମସ୍କାର (or) (nômôskarô)
Ossetian: салам (salam), байрай (bajraj), арфӕ (arfæ)
Palauan: alii
Pashto: سلام‎ (ps) (salām), سلام الېک‎ (slāmālék), السلام عليکم‎ (as-salám alaykúm)
Persian: سلام‎ (fa) (salâm), سلام علیکم‎ (salâmo alaykom) (religious), درود‎ (fa) (dorud) (literary)
Pitcairn-Norfolk: watawieh
Polish: cześć (pl) (informal), witaj (pl), witajcie, witam (more formal), dzień dobry (pl) (formal), siema (pl) (informal), halo (pl) (on phone), serwus (pl) (colloquial), cześka (colloquial), siemanero (colloquial)
Portuguese: oi (pt), olá (pt), (slang) e aí? (pt)
Punjabi: ਸਤਿ ਸ਼੍ਰੀ ਅਕਾਲ (sati śrī akāl)
Rapa Nui: 'iorana
Romani: te aves baxtalo (to a male), te aves baxtali (to a female), te aven baxtale (to two or more people)
Romanian: salut (ro), bună (ro), noroc (ro) (informal), bună ziua (formal), servus (ro)
Russian: приве́т (ru) (privét) (informal), здоро́во (ru) (zdoróvo) (colloquial), здра́вствуйте (ru) (zdrávstvujte) (formal, first "в" is silent), до́брый день (ru) (dóbryj denʹ), здра́вствуй (ru) (zdrávstvuj) (informal, first "в" is silent), салю́т (ru) (saljút)
Rusyn: наздар (nazdar)
Sami:

    Inari Sami: tiervâ
    Northern: dearvva, būres
    Skolt: tiõrv
    Southern: buaregh

Samoan: talofa
Sanskrit: नमस्कार (sa) (namaskāra), नमस्ते (namaste), नमो नमः (namo namaḥ) (formal)
Scots: hullo
Scottish Gaelic: halò (informal), latha math (formal), (informal) hòigh
Serbo-Croatian:

    Cyrillic: здра̏во, ћа̑о, ме̏рха̄ба, селам, бог, бок
    Roman: zdrȁvo (sh), ćȃo (sh), mȅrhāba, selam (sh), bog, bok (sh)

Sesotho: lumela
Shan: please add this translation if you can
Shona: mhoro
Sichuan Yi: please add this translation if you can
Sicilian: ciao, salutamu
Sindhi: هيلو‎
Sinhalese: හලෝ (halō), ආයුබෝවන් (si) (āyubōwan)
Situ: please add this translation if you can
Slovak: ahoj (sk), nazdar (informal), servus (sk) (informal), dobrý deň (formal)
Slovene: žívjo, zdrávo (informal), dóber dán, pozdravljeni (formal)
Somali: ma nabad baa, waa nabad
Sorbian:

    Lower Sorbian: dobry źeń

Sotho: dumela (st)
Spanish: hola (es), buenos días (es), qué tal, buenas tardes (es)
Sundanese: halo
Svan: ხოჩა ლადა̈ღ (xoča ladäɣ)
Swahili: jambo (sw), salaam
Swedish: hallå (sv), hej (sv), god dag (sv) (formal), tjena (sv), hejsan (sv) (informal), tja (sv)
Tagalog: kamusta (tl)/kumusta (tl), musta (tl) (slang), hoy (tl), huy, oy/oi (informal), uy/ui (informal)
Tajik: салом (salom)
Tamil: வணக்கம் (ta) (vaṇakkam)
Tangsa: äshazhoix
Tatar: сәлам (tt) (sälam)
Telugu: నమసకారం (namasakāraṁ), బాగున్నారా (bāgunnārā)
Tetum: please add this translation if you can
Thai: สวัสดี (th) (sà-wàt-dii), สวัสดีครับ (male speaker), สวัสดีค่ะ (female speaker), หวัดดี (wàt-dii)
Tibetan: བཀྲ་ཤིས་བདེ་ལེགས (bkra shis bde legs)
Tigrinya: ሰላም (sälam)
Tongan: mālō e lelei
Tswana: dumela (tn) (singular, as in dumela, rra, "hello sir"), dumelang (tn) (plural, as in dumelang, borra, "hello gentlemen")
Turkish: merhaba (tr), selam (tr)
Turkmen: salam
Tuvan: экии (ekii)
Udmurt: ӟеч (dźeć), чырткем (ćyrtkem), умой (umoj)
Ukrainian: приві́т (uk) (pryvít) (informal), здоро́в був (uk) (zdoróv buv) (informal), добри́день (uk) (dobrýdenʹ) (neutral or formal), чоло́м (čolóm)
Urdu: سلام علیکم‎ (salām-o-alaikum), اسلام علیکم‎ (literally “Peace be upon you”), اسلام علیکم ورحمۃاللہ وبرکاتہ‎ (literally “Peace be upon you & May Allah bless”), آداب‎ (ur) (ādāb)
Uyghur: سالام‎ (salam)
Uzbek: salom (uz)
Venetian: ciao (vec)
Vietnamese: xin chào (vi), chào (vi)
Volapük: glidis
Walloon: bondjoû (wa), a (wa), diewåde (wa) (old)
Welsh: helo (cy), bore da (good morning), dydd da (good day), hylo
West Frisian: hallo, hoi
Winnebago: haho (male speaker), hą (female speaker), hinįkaraginʼ
Xhosa: molo sg, molweni pl
Xibe: ᠪᠠᡳᡨᠠᡴᡡ
ᠨᠠ (baitakū na)
Yakut: эҕэрдэ (eğerde), дорообо (doroobo) (informal)
Yiddish: שלום־עליכם‎ (sholem-aleykhem), אַ גוטן‎ (yi) (a gutn), גוט־מאָרגן‎ (yi) (gut-morgn)
Yoruba: Pẹlẹ o
Yup'ik: waqaa, cama-i
Zapotec: padiull
Zazaki: sılam, namaste
Zhuang: mwngz ndei
Zulu: sawubona (zu) (familiar), sanibonani (plural, respectful)