EXHIBIT 4.1


            CONSENT OF INDEPENDENT REGISTERED PUBLIC ACCOUNTING FIRM

     We consent to the reference to our firm under the caption
"Experts-Independent Registered Public Accounting Firm" and to the use of our
report dated October 31, 2018 in the Amendment No. 1 to the Registration
Statement (File No. 333-227003) and related Prospectus of Guggenheim Defined
Portfolios, Series 1818.

                                                          /s/ Grant Thornton LLP
                                                          ----------------------
                                                              GRANT THORNTON LLP


Chicago, Illinois
October 31, 2018