UNITED STATES

SECURITIES AND EXCHANGE COMMISSION

Washington, D.C. 20549

SCHEDULE 13G

Under the Securities Exchange Act of 1934

(Amendment No. )*

Sun BioPharma, Inc.

^{(Name of Issuer)}

Common Stock, $0.001 par value per share

^{(Title of Class of Securities)}

86664M 107

^{(CUSIP Number)}

September 4, 2015

^{(Date of Event Which Requires Filing of this Statement)}

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

¨ Rule 13d-1(b)

x Rule 13d-1(c)

¨ Rule 13d-1(d)

*The remainder of this cover page shall be filled out for a reporting person's initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter the disclosures provided in a prior cover page.

The information required in the remainder of this cover page shall not be deemed to be "filed" for the purpose of Section 18 of the Securities Exchange Act of 1934 ("Act") or otherwise subject to the liabilities of that section of the Act but shall be subject to all other provisions of the Act (however, see the Notes).

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

CUSIP No. 86664M 107 13G

1	NAMES OF REPORTING PERSONS I.R.S. IDENTIFICATION NOS. OF ABOVE PERSONS (ENTITIES ONLY). Christopher R. Johnson
2	CHECK THE APPROPRIATE BOX IF A MEMBER OF A GROUP* (a) ¨ (b) ¨
3	SEC USE ONLY
4	CITIZENSHIP OR PLACE OF ORGANIZATION USA
NUMBER OF SHARES BENEFICIALLY OWNED BY EACH REPORTING PERSON WITH:		5	SOLE VOTING POWER 2,183,359
		6	SHARED VOTING POWER 0
		7	SOLE DISPOSITIVE POWER 2,183,359
		8	SHARED DISPOSITIVE POWER 0
9	AGGREGATE AMOUNT BENEFICIALLY OWNED BY EACH REPORTING PERSON 2,183,359 SHARES
10	CHECK IF THE AGGREGATE AMOUNT IN ROW (9) EXCLUDES CERTAIN SHARES*
11	PERCENT OF CLASS REPRESENTED BY AMOUNT IN ROW (9) 7.1%
12	TYPE OF REPORTING PERSON* IN

^*SEE INSTRUCTION BEFORE FILLING OUT!

Page 2 of 6

Item 1.

(a) Name of Issuer

 Sun BioPharma, Inc.

(b) Address of Issuer's Principal Executive Offices

 712 Vista Blvd., #305

 Waconia, MN 55387

Item 2.

(a) Name of Person Filing

 Christopher R. Johnson

(b) Address of Principal Business Office or, if none, Residence

 8615 Eagle Creek Circle

 Minneapolis, MN 55378

(c) Citizenship

 USA

(d) Title of Class of Securities

 Common Stock

(e) CUSIP Number

 86664M 107

Item 3. If this statement is filed pursuant to §§ 240.13d 1(b) or 240.13d 2(b) or (c), check whether the person filing is a:

(a)	¨	Broker or dealer registered under section 15 of the Act.
(b)	¨	Bank as defined in section 3(a)(6) of the Act.
(c)	¨	Insurance company as defined in section 3(a)(19) of the Act.
(d)	¨	Investment company registered under section 8 of the Investment Company Act of 1940.
(e)	¨	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E).
(f)	¨	An employee benefit plan or endowment fund in accordance with § 240.13d 1(b)(1)(ii)(F).
(g)	¨	A parent holding company or control person in accordance with § 240.13d 1(b)(1)(ii)(G).
(h)	¨	A savings association as defined in Section 3(b) of the Federal Deposit Insurance Act.
(i)	¨	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940.
(j)	¨	Group, in accordance with § 240.13d 1(b)(1)(ii)(J).

Page 3 of 6

Item 4. Ownership

(a) Amount Beneficially Owned

 2,183,359 Shares

(b) Percent of Class

 7.1%

(c) Number of shares as to which such person has:

(i)	Sole power to vote or to direct the vote
	2,183,359
(ii)	Shared power to vote or to direct the vote
	0
(iii)	Sole power to dispose or to direct the disposition of
	2,183,359
(iv)	Shared power to dispose or to direct the disposition of
	0

Item 5. Ownership of Five Percent or Less of a Class

If this statement is being filed to report the fact that as of the date hereof the reporting person has ceased to be the beneficial owner of more than five percent of the class of securities, check the following o.

Item 6. Ownership of More than Five Percent on Behalf of Another Person.

Not Applicable.

Item 7. Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on By the Parent Holding Company

Not Applicable

Item 8. Identification and Classification of Members of the Group

Not Applicable

Item 9. Notice of Dissolution of Group

Not Applicable

Item 10. Certification

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired and are held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect.

Page 4 of 6

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

September 14, 2015

Date

*

Signature

Christopher R. Johnson

Name/Title

* By signing his name hereto the undersigned does hereby sign this document on behalf of the above-named reporting person pursuant to a power of attorney duly executed thereby.

/s/ Andrew E. Gustafson

Andrew E. Gustafson,

Attorney-in-fact

Attention: Intentional misstatements or omissions of fact constitute Federal criminal violations (See 18 U.S.C. 1001)

Page 5 of 6

Page 6 of 6