From the mother of all front pages, http://www.wikipedia.org/

if you scroll down and click "other languages", you arrive at http://meta.wikimedia.org/wiki/List_of_Wikipedias

Apparently, these tables are updated from s23.org. Some of the links to the language pages could need to be updated. For example No. 244 Sichuan Yi has the article [[:w:Yi language]] and there is no redirect from the link given in this list.

Another list, updated very long ago and only containing the top 50 languages, is given on http://meta.wikimedia.org/wiki/List_of_Wikipedias_by_speakers_per_article

I think the article count of that second list needs to be updated more frequently, perhaps through s23.org, but the number of speakers for each language can only be rough estimates anyway and needs to be updated only very seldom. I have tried to improve that list by looking at the Wikipedia articles for each language. The list is included below. Please report to me any obvious errors, for example where I'm off by a power of magnitude.

I haven't been able to put any numbers on the speakers of Latin, Classic Chinese, Dutch Lower Saxon, or Simple English. Some languages have zero speakers in this list, e.g. Novial and Old Church Slavonic. Is that fair? What numbers do you think should be used? I think we should use the number of people who can be expected to *read* Wikipedia (given literacy and computer access) so Latin should have more than zero, right?

In this table, column 1 is the language code, as used in subdomain names under wikipedia.org, column 2 and 3 are the printable language name in English and English Wikipedia page title, as used in s23.org today, and column 4 is my estimate of the total number of speakers. This table has 256 entries, just like the "List of Wikipedias" page on meta.

aa|Afar|Afar language|1400000 ab|Abkhazian|Abkhazian language|200000 af|Afrikaans|Afrikaans language|6000000 ak|Akan|Akan language|9000000 als|Alemannic|Alemannic language|10000000 am|Amharic|Amharic language|27000000 an|Aragonese|Aragonese language|30000 ang|Anglo-Saxon|Anglo-Saxon language|0 ar|Arabic|Arabic language|323000000 arc|Assyrian Neo-Aramaic|Assyrian Neo-Aramaic language|210000 as|Assamese|Assamese language|13079696 ast|Asturian|Asturian language|550000 av|Avar|Avar language|600000 ay|Aymara|Aymara language|2200000 az|Azeri|Azeri language|30000000 ba|Bashkir|Bashkir language|1000000 bar|Bavarian|Bavarian language|12000000 bat-smg|Samogitian|Samogitian language|500000 bcl|Central Bicolano|Central Bicolano language|2500000 be|Belarusian|Belarusian language|7000000 be-x-old|Belarusian (Tarashkevitsa)|Belarusian (Tarashkevitsa) language|7000000 bg|Bulgarian|Bulgarian language|12000000 bh|Bihari|Bihari language|52000000 bi|Bislama|Bislama language|206000 bm|Bambara|Bambara language|2700000 bn|Bengali|Bengali language|207000000 bo|Tibetan|Tibetan language|6150000 bpy|Bishnupriya Manipuri|Bishnupriya Manipuri language|450000 br|Breton|Breton language|500000 bs|Bosnian|Bosnian language|2000000 bug|Buginese|Buginese language|3500000 bxr|Buryat (Russia)|Buryat (Russia) language|400000 ca|Catalan|Catalan language|12000000 cbk-zam|Zamboanga Chavacano|Zamboanga Chavacano language|607000 cdo|Min Dong|Min Dong language|9100000 ce|Chechen|Chechen language|1330000 ceb|Cebuano|Cebuano language|28000000 ch|Chamorro|Chamorro language|60000 cho|Choctaw|Choctaw language|9200 chr|Cherokee|Cherokee language|15000 chy|Cheyenne|Cheyenne language|1700 co|Corsican|Corsican language|400000 cr|Cree|Cree language|50000 crh|Crimean Tatar|Crimean Tatar language|400000 cs|Czech|Czech language|12000000 csb|Kashubian|Kashubian language|50000 cu|Old Church Slavonic|Old Church Slavonic language|0 cv|Chuvash|Chuvash language|2000000 cy|Welsh|Welsh language|600000 da|Danish|Danish language|5300000 de|German|German language|124000000 diq|Zazaki|Zazaki language|2500000 dsb|Lower Sorbian|Lower Sorbian language|14000 dv|Divehi|Divehi language|300000 dz|Dzongkha|Dzongkha language|600000 ee|Ewe|Ewe language|3000000 el|Greek|Greek language|12000000 eml|Emilian-Romagnol|Emilian-Romagnol language|2000000 en|English|English language|1000000000 eo|Esperanto|Esperanto language|2000000 es|Spanish|Spanish language|420000000 et|Estonian|Estonian language|1100000 eu|Basque|Basque language|580000 fa|Persian|Persian language|110000000 ff|Fula|Fula language|10000000 fi|Finnish|Finnish language|6000000 fiu-vro|Võro|Võro language|70000 fj|Fijian|Fijian language|550000 fo|Faroese|Faroese language|80000 fr|French|French language|130000000 frp|Franco-Provençal/Arpitan|Franco-Provençal/Arpitan language|113000 fur|Friulian|Friulian language|600000 fy|West Frisian|West Frisian language|400000 ga|Irish|Irish language|100000 gd|Scottish Gaelic|Scottish Gaelic language|60000 gl|Galician|Galician language|3500000 glk|Gilaki|Gilaki language|2000000 gn|Guarani|Guarani language|7000000 got|Gothic|Gothic language|0 gu|Gujarati|Gujarati language|46000000 gv|Manx|Manx language|1745 ha|Hausa|Hausa language|39000000 hak|Hakka|Hakka language|34000000 haw|Hawaiian|Hawaiian language|2000 he|Hebrew|Hebrew language|7000000 hi|Hindi|Hindi language|330000000 ho|Hiri Motu|Hiri Motu language|120000 hr|Croatian|Croatian language|5000000 hsb|Upper Sorbian|Upper Sorbian language|55000 ht|Haitian|Haitian language|7800000 hu|Hungarian|Hungarian language|14500000 hy|Armenian|Armenian language|7000000 hz|Herero|Herero language|133000 ia|Interlingua|Interlingua language|1500 id|Indonesian|Indonesian language|200000000 ie|Interlingue|Interlingue language|0 ig|Igbo|Igbo language|20000000 ii|Sichuan Yi|Sichuan Yi language|6000000 ik|Inupiak|Inupiak language|10000 ilo|Ilokano|Ilokano language|7000000 io|Ido|Ido language|2500 is|Icelandic|Icelandic language|300000 it|Italian|Italian language|70000000 iu|Inuktitut|Inuktitut language|30000 ja|Japanese|Japanese language|127000000 jbo|Lojban|Lojban language|0 jv|Javanese|Javanese language|100000000 ka|Georgian|Georgian language|4100000 kab|Kabyle|Kabyle language|7000000 kg|Kongo|Kongo language|7000000 ki|Kikuyu|Kikuyu language|5347000 kj|Kuanyama|Kuanyama language|670000 kk|Kazakh|Kazakh language|12000000 kl|Greenlandic|Greenlandic language|54000 km|Khmer|Khmer language|16000000 kn|Kannada|Kannada language|40000000 ko|Korean|Korean language|71000000 kr|Kanuri|Kanuri language|4000000 ks|Kashmiri|Kashmiri language|4600000 ksh|Ripuarian|Ripuarian language|250000 ku|Kurdish|Kurdish language|20000000 kv|Komi|Komi language|293000 kw|Cornish|Cornish language|3500 ky|Kirghiz|Kirghiz language|3136733 la|Latin|Latin language| lad|Ladino|Ladino language|110000 lb|Luxembourgish|Luxembourgish language|300000 lbe|Lak|Lak language|120000 lg|Luganda|Luganda language|3110000 li|Limburgian|Limburgian language|1600000 lij|Ligurian|Ligurian language|0 lmo|Lombard|Lombard language|9130000 ln|Lingala|Lingala language|10000000 lo|Lao|Lao language|5225552 lt|Lithuanian|Lithuanian language|4000000 lv|Latvian|Latvian language|1500000 map-bms|Banyumasan|Banyumasan language|15000000 mg|Malagasy|Malagasy language|6000000 mh|Marshallese|Marshallese language|43900 mi|Maori|Maori language|150000 mk|Macedonian|Macedonian language|2000000 ml|Malayalam|Malayalam language|35700000 mn|Mongolian|Mongolian language|5700000 mo|Moldovan|Moldovan language|2030000 mr|Marathi|Marathi language|90000000 ms|Malay|Malay language|30000000 mt|Maltese|Maltese language|600000 mus|Muscogee|Muscogee language|4300 my|Burmese|Burmese language|42000000 mzn|Mazandarani|Mazandarani language|3000000 na|Nauruan|Nauruan language|6000 nah|Nahuatl|Nahuatl language|1500000 nap|Neapolitan|Neapolitan language|7500000 nds|Low Saxon|Low Saxon language|10000000 nds-nl|Dutch Low Saxon|Dutch Low Saxon language| ne|Nepali|Nepali language|40000000 new|Newar / Nepal Bhasa|Newar / Nepal Bhasa language|1000000 ng|Ndonga|Ndonga language|690000 nl|Dutch|Dutch language|23000000 nn|Norwegian (Nynorsk)|Norwegian (Nynorsk) language|500000 no|Norwegian (Bokmål)|Norwegian (Bokmål) language|5000000 nov|Novial|Novial language|0 nrm|Norman|Norman language|20000 nv|Navajo|Navajo language|178000 ny|Chichewa|Chichewa language|9300000 oc|Occitan|Occitan language|1900000 om|Oromo|Oromo language|25000000 or|Oriya|Oriya language|31000000 os|Ossetian|Ossetian language|500000 pa|Punjabi|Punjabi language|88000000 pag|Pangasinan|Pangasinan language|1500000 pam|Kapampangan|Kapampangan language|2300000 pap|Papiamentu|Papiamentu language|329000 pdc|Pennsylvania German|Pennsylvania German language|300000 pi|Pali|Pali language|0 pih|Norfolk|Norfolk language|616 pl|Polish|Polish language|46000000 pms|Piedmontese|Piedmontese language|2000000 ps|Pashto|Pashto language|50000000 pt|Portuguese|Portuguese language|213000000 qu|Quechua|Quechua language|10400000 rm|Romansh|Romansh language|70000 rmy|Romani|Romani language|4800000 rn|Kirundi|Kirundi language|4600000 ro|Romanian|Romanian language|28000000 roa-rup|Aromanian|Aromanian language|300000 roa-tara|Tarantino|Tarantino language|900000 ru|Russian|Russian language|255000000 rw|Kinyarwanda|Kinyarwanda language|7000000 sa|Sanskrit|Sanskrit language|200000 sc|Sardinian|Sardinian language|2500000 scn|Sicilian|Sicilian language|10000000 sco|Scots|Scots language|1500000 sd|Sindhi|Sindhi language|21300000 se|Northern Sami|Northern Sami language|20000 sg|Sango|Sango language|2000000 sh|Serbo-Croatian|Serbo-Croatian language|20000000 si|Sinhalese|Sinhalese language|15000000 simple|Simple English|Simple English language| sk|Slovak|Slovak language|6000000 sl|Slovenian|Slovenian language|2200000 sm|Samoan|Samoan language|370337 sn|Shona|Shona language|7000000 so|Somali|Somali language|10000000 sq|Albanian|Albanian language|6000000 sr|Serbian|Serbian language|11000000 ss|Swati|Swati language|1706924 st|Sesotho|Sesotho language|5000000 stq|Saterland Frisian|Saterland Frisian language|2000 su|Sundanese|Sundanese language|27000000 sv|Swedish|Swedish language|9000000 sw|Swahili|Swahili language|40000000 ta|Tamil|Tamil language|74000000 te|Telugu|Telugu language|80000000 tet|Tetum|Tetum language|800000 tg|Tajik|Tajik language|4380000 th|Thai|Thai language|50000000 ti|Tigrinya|Tigrinya language|6700000 tk|Turkmen|Turkmen language|9000000 tl|Tagalog|Tagalog language|87000000 tlh|Klingon|Klingon language|16 tn|Tswana|Tswana language|4407174 to|Tongan|Tongan language|105000 tokipona|Tokipona|Tokipona language|3 tpi|Tok Pisin|Tok Pisin language|4000000 tr|Turkish|Turkish language|80000000 ts|Tsonga|Tsonga language|3275105 tt|Tatar|Tatar language|8000000 tum|Tumbuka|Tumbuka language|2000000 tw|Twi|Twi language|7000000 ty|Tahitian|Tahitian language|120000 udm|Udmurt|Udmurt language|550000 ug|Uyghur|Uyghur language|10000000 uk|Ukrainian|Ukrainian language|41000000 ur|Urdu|Urdu language|104000000 uz|Uzbek|Uzbek language|18500000 ve|Venda|Venda language|750000 vec|Venetian|Venetian language|2200000 vi|Vietnamese|Vietnamese language|80000000 vls|West Flemish|West Flemish language|1160000 vo|Volapük|Volapük language|25 wa|Walloon|Walloon language|600000 war|Waray-Waray|Waray-Waray language|3000000 wo|Wolof|Wolof language|6700000 wuu|Wu|Wu language|77000000 xal|Kalmyk|Kalmyk language|518500 xh|Xhosa|Xhosa language|7900000 yi|Yiddish|Yiddish language|3000000 yo|Yoruba|Yoruba language|21000000 za|Zhuang|Zhuang language|14000000 zea|Zealandic|Zealandic language|250000 zh|Chinese|Chinese language|1080000000 zh-classical|Classical Chinese|Classical Chinese language| zh-min-nan|Min Nan|Min Nan language|46000000 zh-yue|Cantonese|Cantonese language|66000000 zu|Zulu|Zulu language|26000000