Report of Foreign Issuer (6-k)

UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

Form 6-K

REPORT OF FOREIGN PRIVATE ISSUER PURSUANT TO RULE 13a-16 OR 15d-16 UNDER THE

SECURITIES EXCHANGE ACT OF 1934

For the month of September 2018.

Commission File Number: 001-35755

DELTA TECHNOLOGY HOLDINGS LIMITED

(Translation of registrant’s name into English)

16 Kaifa Avenue

Danyang, Jiangsu, China 212300

Tel: +86 511-8673-3102

(Address of principal executive office)

Indicate by check mark whether the registrant files or will file annual reports under cover of Form 20-F or Form 40-F.

Form 20-F x Form 40-F ¨

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(1): ¨

Note : Regulation S-T Rule 101(b)(1) only permits the submission in paper of a Form 6-K if submitted solely to provide an attached annual report to security holders.

Indicate by check mark if the registrant is submitting the Form 6-K in paper as permitted by Regulation S-T Rule 101(b)(7): ¨

Note : Regulation S-T Rule 101(b)(7) only permits the submission in paper of a Form 6-K if submitted to furnish a report or other document that the registrant foreign private issuer must furnish and make public under the laws of the jurisdiction in which the registrant is incorporated, domiciled or legally organized (the registrant’s “home country”), or under the rules of the home country exchange on which the registrant’s securities are traded, as long as the report or other document is not a press release, is not required to be and has not been distributed to the registrant’s security holders, and, if discussing a material event, has already been the subject of a Form 6-K submission or other Commission filing on EDGAR.

On September 14, 2018, Delta Technology Holdings Limited (the “ Company ”) received a notification letter from the Nasdaq Listing Qualifications Staff of The NASDAQ Stock Market LLC (“ Nasdaq ”) notifying the Company that the minimum bid price per share for its common shares has been below $1.00 for a period of 30 consecutive business days and the Company therefore no longer meets the minimum bid price requirements set forth in Nasdaq Listing Rule 5550(a)(2).

The notification received has no immediate effect on the listing of the Company’s common stock on Nasdaq. Under the Nasdaq Listing Rules, the Company has until March 13, 2019 to regain compliance. If at any time during such 180-day period the closing bid price of the Company’s common shares is at least $1 for a minimum of 10 consecutive business days, Nasdaq will provide the Company written confirmation of compliance.

If the Company does not regain compliance during such 180-day period, the Company may be eligible for an additional 180 calendar days, provided that the Company meets the continued listing requirement for market value of publicly held shares and all other initial listing standards for Nasdaq except for Nasdaq Listing Rule 5550(a)(2), and provide a written notice of its intention to cure this deficiency during the second compliance period, by effecting a reverse stock split, if necessary.

The Company, by filing this Form 6-K, discloses its receipt of the notification from Nasdaq in accordance with Nasdaq Listing Rule 5810(b).

SIGNATURES

Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.