Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q X Quarterly Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the quarterly period ended March 31, 2019. OR ___ Transition Report Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 For the transition period from __________ to __________. Commission file number 001-13643 ONEOK, Inc. (Exact name of registrant as specified in its charter) Oklahoma 73-1520922 (S ...

Table of Contents UNITED STATES SECURITIES AND EXCHANGE COMMISSION WASHINGTON, D.C. 20549 FORM 10-K X ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018. OR __ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from __________ to __________. Commission file number 001-13643 ONEOK, Inc. (Exact name of registrant as specified in its charter) Oklahoma 73-1520922 (State o ...