Petitioner Iron Arrow Honor Society is an all-male honorary organization founded by the first president of the University of Miami to honor outstanding University men. Traditionally, the Society has conducted its initiation ceremony on a “tapping” mound outside the student union building on University property. In 1972 Congress enacted § 901(a) of Title IX of the Education Amendments, 86 Stat. 373, 20 U. S. C. § 1681(a), and in 1974 the Department of Health, Education, and Welfare promulgated regulations implementing the statute. Regulation 86.31(b)(7) provides that “a recipient [of federal funds] shall not, on the basis of sex; ... (7) [a]id or perpetuate discrimination against any person by providing significant assistance to any agency, organization, or person which discriminates on the basis of sex in providing any aid, benefit or service to students or employees.” 45 CFR § 86.31(b)(7) (1975) (emphasis added) (recodified at 34 CFR § 106.31(b)(7) (1982)).
In 1976 the Secretary notified the University’s president of its determination that the University was rendering “significant assistance” within the meaning of the regulation to Iron Arrow. The University advised the Secretary that it wished to comply with Title IX, but asked for time to negotiate with Iron Arrow about changing its membership policy; the Secretary agreed, but only upon the condition that the University *69ban the “tapping” ceremony on campus until the question was resolved.
The University thereafter prohibited the “tapping” ceremony, and Iron Arrow responded by suing the Secretary in the United States District Court for the Southern District of Florida. It sought declaratory and injunctive relief to prevent the Secretary from interpreting Regulation 86.31(b)(7) so as to require the University to ban Iron Arrow’s activities from campus. The District Court held that Iron Arrow had no standing to challenge the Secretary’s action and the regulations, but this determination was reversed by the Court of Appeals for the Fifth Circuit. Iron Arrow Honor Society v. Calif ano, 597 F. 2d 590, 591 (1979). The District Court then granted summary judgment for the Secretary, Iron Arrow Honor Society v. Hustedler, 499 F. Supp. 496 (1980), and the Court of Appeals for the Fifth Circuit affirmed. Iron Arrow Honor Society v. Schweiker, 652 F. 2d 445 (1981). We granted Iron Arrow’s petition for certiorari, vacated the decision of the Court of Appeals for the Fifth Circuit, and remanded for further consideration in light of North Haven Board of Education v. Bell, 456 U. S. 512 (1982). Iron Arrow Honor Society v. Schweiker, 458 U. S. 1102 (1982). On remand the Court of Appeals for the Fifth Circuit again affirmed with one judge dissenting. 702 F. 2d 549 (1983).
After our remand but before the decision of the Court of Appeals for the Fifth Circuit, the president of the University wrote a letter to the chief of Iron Arrow. It stated the University’s unequivocal position that Iron Arrow cannot return to campus as a University organization nor conduct its activities on campus until it discontinues its discriminatory membership policy. Letter from Edward T. Foote II to C. Rhea Warren (Sept. 23, 1982), reprinted in App. to Brief for Federal Respondents, la-4a. The Trustee Executive Committee had adopted that position on July 15, 1980, determining that Iron Arrow may return to campus only if it satisfies the code for all student organizations, a code which includes a policy of nondiscrimination. The president’s letter moreover *70informed Iron Arrow that the University would maintain that position, regardless of the outcome of Iron Arrow’s lawsuit. Specifically the letter stated:
“The question is not only what the law requires. The most important question is what our University should do, in fairness to all students, whether the law requires it or not.
“To avoid any ambiguity that might be present because of the passage of time or change of University administrations, I have instructed counsel for the University to inform the Courts of the University’s policy.” Id., at 2a-4a (emphasis in original).
The president further informed Iron Arrow that he was making the letter public and that he was sending a copy to all of Iron Arrow’s undergraduate members. Id., at 4a.
Both before the Court of Appeals for the Fifth Circuit and now before this Court in the Secretary’s response to Iron Arrow’s latest petition for certiorari, the Secretary has argued that that letter renders the case moot. For the reasons which follow, we agree that the case has become moot during the pendency of this litigation.
Federal courts lack jurisdiction to decide moot cases because their constitutional authority extends only to actual cases or controversies. DeFunis v. Odegaard, 416 U. S. 312, 316 (1974). To satisfy the Art. Ill case-or-controversy requirement, a litigant must have suffered some actual injury that can be redressed by a favorable judicial decision. Simon v. Eastern Kentucky Welfare Rights Organization, 426 U. S. 26, 38 (1976). We think that no resolution of the present dispute between these parties can redress Iron Arrow’s asserted grievance. Whatever the correctness of the Secretary’s interpretation of the regulation in question, the University has stated unequivocally that it will not allow Iron Arrow to conduct its initiation activities on University prop*71erty as long as it refuses to admit women. Thus the dispute as to how the regulation should be interpreted, or the extent to which it faithfully implements the statute, is classically “moot.” It is the action of the University, not that of the Secretary, which excludes Iron Arrow.
The Court of Appeals concluded by a divided vote that the case was not moot because it could still grant some relief to Iron Arrow. 702 F. 2d, at 552. It stated that the Secretary could still require the University to take other steps to comply with Title IX in addition to banning Iron Arrow from campus. For example, it could require the University to abolish all historical ties with Iron Arrow, refuse to allow Iron Arrow to use the University’s name, etc. Ibid. The court concluded that if it decided in Iron Arrow’s favor,. it could issue an injunction which “would serve to insulate the plaintiffs from all of these appropriate additional enforcement actions.” Ibid.
Whether or not these would be “appropriate additional enforcement actions,” neither we nor the Court of Appeals need decide, since the Secretary is not requesting the University to take such additional steps, see Brief for Federal Respondents 13, and Iron Arrow has not sought in this lawsuit to prevent the University from doing so. Future positions taken by the parties might bring such issues into controversy, but that possibility is simply too remote from the present controversy to keep this case alive. See Golden v. Zwickler, 394 U. S. 103, 109 (1969).1
In rejecting the Secretary’s argument that the case is moot, the Court of Appeals also relied on a line of cases from this Court supporting the proposition that the “ ‘[voluntary *72discontinuance of an alleged illegal activity does not operate to remove a case from the ambit of judicial power.’ ” 702 F. 2d, at 553 (quoting Walling v. Helmerich & Payne, 323 U. S. 37, 43 (1944)). As the dissent noted, however, most of those cases discuss whether voluntary discontinuance of challenged activities by a defendant moots a lawsuit. 702 F. 2d, at 565, 567 (Roney, J., dissenting). But see St. Paul Fire & Marine Insurance Co. v. Barry, 438 U. S. 531, 537-538 (1978) (involving subsequent acts of a third party). Defendants face a heavy burden to establish mootness in such cases because otherwise they would simply be free to “return to [their] old ways” after the threat of a lawsuit had passed. United States v. W. T. Grant Co., 345 U. S. 629, 632 (1953). Thus they must establish that “there is no reasonable likelihood that the wrong will be repeated.” Id., at 633 (citation omitted).
This case, however, concerns the effect of the voluntary acts of a third-party nondefendant.2 It is not the typical case where it could be argued that the University has taken its position only in order to escape the threat of an injunction. Indeed, Iron Arrow does not challenge the University’s conduct in this lawsuit. Assuming that the “voluntary discontinuance” line of cases nonetheless applies to this different situation, the letter from the president expresses the University’s voluntary and unequivocal intention to exclude Iron Arrow’s activities from campus. Because the University has announced its decision to Iron Arrow, the public, and the courts, we conclude that there is “no reasonable likelihood” that the University will later change its mind and decide to invite Iron Arrow to return.
Because of the position that the University has taken irrespective of the outcome of this lawsuit, we conclude that the *73case is moot and that the Court of Appeals had no jurisdiction to decide it. Accordingly, we grant the petition for a writ of certiorari, vacate the judgment of the Court of Appeals for the Fifth Circuit, and remand to that court for entry of an appropriate order directing the District Court to dismiss the action as moot. See County of Los Angeles v. Davis, 440 U. S. 625, 634 (1979); United States v. Munsingwear, Inc., 340 U. S. 36, 39-40 (1950).
It is so ordered.
Justice Marshall and Justice Blackmun would deny certiorari.Iron Arrow also appears to have sought a declaration of its rights under Regulation 86.31(b)(7) pursuant to 28 U. S. C. § 2201. Iron Arrow Honor Society v. Hustedler, 499 F. Supp. 496, 499 (SD Fla. 1980). It, however, has no standing under that section to seek a generalized declaration of its rights against future actions of the Secretary. See Public Service Comm’n v. WycoffCo., 344 U. S. 237, 241-249 (1952).
The University is not a named defendant in this action. The District Court did, however, join the University as an indispensable party under Federal Rule of Civil Procedure 19 in order to assure that the court could award adequate relief to Iron Arrow if it prevailed. 499 F. Supp., at 499.