<SEC-DOCUMENT>0001193125-18-190205-index.html : 20180612
<SEC-HEADER>0001193125-18-190205.hdr.sgml : 20180612
<ACCEPTANCE-DATETIME>20180612115806
ACCESSION NUMBER:		0001193125-18-190205
CONFORMED SUBMISSION TYPE:	11-K
PUBLIC DOCUMENT COUNT:		2
CONFORMED PERIOD OF REPORT:	20171231
FILED AS OF DATE:		20180612
DATE AS OF CHANGE:		20180612

FILER:

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			UNITIL CORP
		CENTRAL INDEX KEY:			0000755001
		STANDARD INDUSTRIAL CLASSIFICATION:	ELECTRIC & OTHER SERVICES COMBINED [4931]
		IRS NUMBER:				020381573
		STATE OF INCORPORATION:			NH
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		11-K
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	001-08858
		FILM NUMBER:		18893957

	BUSINESS ADDRESS:	
		STREET 1:		6 LIBERTY LANE WEST
		CITY:			HAMPTON
		STATE:			NH
		ZIP:			03842
		BUSINESS PHONE:		6037736504

	MAIL ADDRESS:	
		STREET 1:		6 LIBERTY LANE WEST
		CITY:			HAMPTON
		STATE:			NH
		ZIP:			03842
</SEC-HEADER>
<DOCUMENT>
<TYPE>11-K
<SEQUENCE>1
<FILENAME>d598890d11k.htm
<DESCRIPTION>FORM 11-K
<TEXT>
Document 1 - file: d598890d11k.htm

</DOCUMENT>
<DOCUMENT>
<TYPE>EX-23.1
<SEQUENCE>2
<FILENAME>d598890dex231.htm
<DESCRIPTION>EX-23.1
<TEXT>
Document 2 - file: d598890dex231.htm

</DOCUMENT>
</SEC-DOCUMENT>