The '''Roman Catholic Diocese of Springfield in Illinois''' is an ecclesiastical territory or Cathedral of the Immaculate Conception.  

A diocese of the Metropolitan Province of Chicago, the Archbishop of Chicago. The bishop of the Diocese of Springfield is Bishop George Lucas. The Bishop Emeritus is Daniel L. Ryan.  

The Diocese of Springfield in Illinois comprises the Counties of Adams, Bond, Brown, Calhoun, Cass, Christian, Clark, Coles, Crawford, Cumberland, Douglas, Edgar, Effingham, Fayette, Greene, Jasper, Jersey, Macon, Macoupin, Madison, Menard, Moultrie, Montgomery, Morgan, Pike, Sangamon, Scott, and Shelby.

The Diocese of Springfield in Illinois was established on July 29, 1853 as the '''Diocese of Quincy'''. Its name was changed to the '''Diocese of Alton''' on January 9, 1857, and its current name came into being on October 26, 1923.

==Statistics==
''As of 2007'':<ref>The Official Catholic Directory 2007 (published in New Providence, New Jersey: P. J. Kennedy and Sons, 2007)</ref>
* 151,601 Catholics
* 132 parishes
* 87 active priests; 62 religious order priests
* 122 diocesan priests (including retired and serving outside the diocese)
* 6 Catholic hospitals

==Catholic schools==
* 1 seminary
* 44 elementary schools 

===6 high schools===
* Marquette Catholic High School, Alton, Illinois
* Quincy Notre Dame High School, Quincy, Illinois
* Routt Catholic High School, Jacksonville, Illinois
* Sacred Heart-Griffin High School, Springfield, Illinois
* St. Anthony High School, Effingham, Illinois
* St. Teresa High School, Decatur, Illinois

This does not count Ursuline Academy, closed in 2007.

===1 college===
* Springfield College

===1 university===
* Quincy University

==Leadership==
* '''His Excellency George J. Lucas, Bishop of the Diocese of Springfield in Illinois''': named as eighth bishop of the diocese by Pope John Paul II on 1999-10-19; installed 1999-12-14. At the time of his appointment, Msgr. Lucas was president-rector of Kenrick-Glennon Seminary in St. Louis.<ref name="diohistory">[http://www.dio.org/about/index.php?file=history "History of the Diocese"], official diocese website.  Retrieved 2006-11-11.</ref>

{{diocesi della chiesa cattolica
|nome=Springfield in Illinois
|latino=Dioecesis Campifontis in Illinois
|titolo=vescovo
|titolare=George Joseph Lucas
|emeriti=Daniel Leo Ryan
|vicario=
|stato=Stati Uniti
|ritoliturgico=romano
|eretta=29 luglio 1853
|stemma=
|mappa=
|mappacollocazione=
|mappaprovincia=
|suffraganeadi=arcidiocesi di Chicago
|regione=VII (IL, IN, WI)
|battezzati=161.325
|popolazione=1.106.124
|proporzione=14,6
|sacerdotisecolari=119
|sacerdotiregolari=59
|sacerdoti=178
|battezzatipersacerdote=906
|diaconi=5
|religiosi=90
|religiose=563
|vicariati=
|parrocchie=156
|superficie=39.195
|indirizzo=P.O. Box 3187, 1615 W. Washington St., Springfield, IL 62708-3187
|telefono=(217)698-8500
|fax=698-0802
|sito=www.dio.org
|email=
|anno=2005
|ch=spil
}}

La '''diocesi di Springfield in Illinois''' (in latino: ''Dioecesis Campifontis in Illinois'') è una sede della VII (IL, IN, WI). Nel 2004 contava 161.325 battezzati su 1.106.124 abitanti. È attualmente retta dal vescovo George Joseph Lucas.
==Territorio==
La diocesi comprende le seguenti contee dello stato statunitense dell'Adams, Bond, Brown, Calhoun, Cass, Christian, Clark, Coles, Crawford, Cumberland, Douglas, Edgar, Effingham, Fayette, Greene, Jasper, Jersey, Macon, Macoupin, Madison, Menard, Montgomery, Morgan, Moultrie, Pike, Sangamon, Scott e Shelby.

La sede vescovile è la città di Springfield, dove si trova la cattedrale dell'Immacolata Concezione (''Cathedral of the Immaculate Conception''). 

Il territorio è suddiviso in 156 parrocchie.

==Storia==
La diocesi di Quincy fu eretta il Chicago (oggi arcidiocesi). 

Il 9 gennaio 1857 assunse il nome di diocesi di Alton.

Il 7 gennaio 1887 cedette una porzione del suo territorio a vantaggio dell'erezione della diocesi di Belleville.