Nexpoint Residential Trust (NXRT): Highland Capital Management Doubles Down On REIT

SECURITIES AND EXCHANGE COMMISSION

WASHINGTON, DC 20549

SCHEDULE 13D

(Rule 13d-101)

INFORMATION TO BE INCLUDED IN STATEMENTS FILED PURSUANT

TO § 240.13d-1(a) AND AMENDMENTS THERETO FILED

PURSUANT TO § 240.13d-2(a)

(Amendment No. 6)

NEXPOINT
RESIDENTIAL TRUST, INC.

(Name of Issuer)

Common Stock, $0.01 par value per share

(Title of Class of Securities)

65341D102

(CUSIP Number)

Thomas Surgent, Chief Compliance Officer

Highland Capital Management, L.P.

300 Crescent Court, Suite 700

Dallas, TX 75201

(Name,
Address and Telephone Number of Person Authorized to Receive Notices and Communications)

July 20, 2016

(Date of Event Which Requires Filing of this Statement)

If the filing
person has previously filed a statement on Schedule 13G to report the acquisition that is the subject of this Schedule 13D, and is filing this schedule because of §§ 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following
box.  ¨

SCHEDULE 13D/A

This Amendment No. 6 (this Amendment) is being filed on behalf of Highland Capital Management, L.P., a Delaware limited
partnership (Highland Capital), James D. Dondero, and Nancy Marie Dondero (collectively, the Reporting Persons), and amends the Schedule 13D filed on March 26, 2015, as subsequently amended on April 14, 2015, as
subsequently amended on April 23, 2015, as subsequently amended on April 24, 2015, as subsequently amended on September 2, 2015 and as subsequently amended on October 19, 2015. This Amendment updates the stock ownership
information for the Schedule 13D. The Schedule 13D is supplementally amended as follows.

Item 3. Source and Amount of Funds.

The Reporting Persons received an aggregate of 2,470,129 shares of Common Stock, par value $0.01 per share (the Common Stock) in
connection with the consummation of the separation of the Issuer from NexPoint Credit Strategies Fund (the Spin-Off). As of July 20, 2016, the Reporting Persons had purchased additional shares of Common Stock with working capital in
open market purchases for an aggregate purchase price of approximately $15,791,133.41.

Item 5. Interest in Securities of the Issuer.

(a) As of July 20, 2016, (i) Highland Capital may be deemed to beneficially own 1,646,951.26 shares of Common Stock, which represents
approximately 7.74% of the outstanding Common Stock, (ii) James D. Dondero may be deemed to beneficially own 3,588,261.6798 shares of Common Stock, which represents approximately 16.87% of the outstanding Common Stock, and (iii) Nancy
Marie Dondero, in her capacity of trustee of a trust, may deemed to beneficially own 1,868,331.5774 shares of Common Stock, which represents approximately 8.79% of the outstanding Common Stock. James D. Dondero has the right to acquire beneficial
ownership of the 1,868,331.5774 shares of Common Stock owned by the trust referred to in the preceding sentence.

(b)

(c) Annex A attached hereto lists all transactions in the Common Stock during the past 60 days by the Reporting Persons. Except as otherwise
noted, the transactions in the Common Stock were effected in the open market.

(d) No person other than the Reporting Persons is known to have the right to receive, or the
power to direct the receipt of dividends from, or proceeds from the sale of, the Common Stock.

(e) Not applicable.

SIGNATURE

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

Dated: July 22, 2016

ANNEX A

TRANSACTIONS

The following table sets
forth all transactions with respect to the Common Stock effected in the last sixty (60) days by the Reporting Persons or on behalf of the Reporting Persons in respect of the shares of Common Stock, inclusive of any transactions effected through
4:00 p.m., New York City time, on July 21, 2016.