POWER OF ATTORNEY

	Know all by these presents, that the undersigned hereby makes, constitutes and
appoints each of James L. Waters and Susan Murr as the undersigned's true and
lawful attorney in-fact, with power to act without the others and with full
power and authority as hereinafter described on behalf of and in the name, place
and stead of the undersigned to:

(1)	prepare, execute, acknowledge, deliver and file Forms 3, 4 and 5 (including
any amendments thereto and successor Forms) and Forms 144 (including any
amendments thereto and successor Forms) with respect to the securities of
Cullen/Frost Bankers, Inc., a Texas corporation (the "Company"), with the United
States Securities and Exchange Commission, any national securities exchanges and
any other governmental entity or trading system deemed necessary or advisable by
such attorney-in-fact under Section 16(a) of the Securities Exchange Act of 1934
and the rules and regulations promulgated thereunder, as amended from time to
time (the "Exchange Act"), and under Rule 144 of the Securities Act of 1933 and
the rules and regulations promulgated thereunder, as amended from time to time
(the "Securities Act");

(2)	seek or obtain, as the undersigned's representative and on the undersigned's
behalf, information on transactions in the Company's securities from any third
party, including brokers, employee benefit plan administrators and trustees, and
the undersigned hereby authorizes any such person to release any such
information to such attorney in fact and approves and ratifies any such release
of information; and

(3)	perform any and all other acts which in the discretion of such
attorney-in-fact are necessary or desirable for and on behalf of the undersigned
in connection with the foregoing.

The undersigned acknowledges that:

(1)	this Power of Attorney authorizes, but does not require, such
attorney-in-fact to act in their discretion on information provided to such
attorney-in-fact without independent verification of such information;

(2)	any documents prepared and/or executed by such attorney-in-fact on behalf of
the undersigned pursuant to this Power of Attorney will be in such form and will
contain such information and disclosure as such attorney-in-fact, in his or her
discretion, deems necessary or desirable;

(3)	neither the Company nor such attorney-in-fact assumes (i) any liability for
the undersigned's responsibility to comply with the requirements of the Exchange
Act or Securities Act, (ii) any liability of the undersigned for any failure to
comply with such requirements or (iii) any obligation or liability of the
undersigned for profit disgorgement under Section 16(b) of the Exchange Act; and

(4)	this Power of Attorney does not relieve the undersigned from responsibility
for compliance with the undersigned's obligations under the Exchange Act,
including without limitation the reporting requirements under Section 16 of the
Exchange Act, or the Securities Act, including without limitation the
requirements of Rule 144.

	The undersigned hereby gives and grants to each such attorney-in-fact severally
full power and authority to do and perform, in the name and on behalf of the
undersigned, and in any and all capacities, every act and thing whatsoever
requisite, necessary or appropriate to be done in and about the foregoing
matters, as fully and to all intents and purposes as the undersigned might or
could do in person, with full power of substitution and resubstitution, hereby
ratifying and approving all that such attorney-in-fact, or such
attorney-in-fact's substitute or substitutes, shall lawfully do or cause to be
done by virtue of this Power of Attorney and the rights and powers herein
granted.

	This Power of Attorney shall remain in full force and effect until either
revoked by the undersigned in a signed writing delivered to such
attorneys-in-fact or until such time as the undersigned is no longer required to
file Forms 3, 4 and 5 and Forms 144 with respect to the undersigned's holdings
of and transactions in securities issued by the Company.

	IN WITNESS WHEREOF, the undersigned has caused this Power of Attorney to be
executed on this 27th day of April, 2020.

Signature

/s/ Anthony R. Chase


STATE OF TEXAS

COUNTY OF TEXAS

	On this 27th day of April, 2020, Anthony R. Chase personally appeared before
me, and acknowledged that he executed the foregoing instrument for the purposes
therein contained.

	IN WITNESS WHEREOF, I have hereunto set my hand and official seal.


	/s/ Rekayla A. Franklin
	Notary Public, State of Texas
	My Commission Expires 12-06-2021
        ID No. 129645856