The final act again opens at Lady Wishfort's house, having apparently skipped some time as the audience finds Lady Wishfort berating Foible for her role in Mirabell's scheme. Lady Wishfort threatens to send her back out on the street while Foible attempts to make excuses for her participation, pleading that she is only a poor, ignorant woman. Lady Wishfort says that Waitwell is already in custody and that Foible will be sent to jail as well.
As Lady Wishfort exits, Mrs. Fainall enters and remarks on Foible's lamentable state. Foible reveals that the letter sent to Lady Wishfort by Ms. Marwood gave the circumstances of her realization of the plot, hearing Foible from in the closet, but Lady Wishfort did not get to the part about Mrs. Fainall's involvement before Waitwell and Foible were able to wrest the letter from her. Mr. Fainall does know of Mrs. Fainall's previous affair with Mirabell, however, so they will be separating. However, Foible believes leverage can be exerted on Mr. Fainall by proving he and Ms. Marwood have been in a relationship. Mincing enters and tells Foible that Ms. Millamant and Mirabell would like to see her, that Mirabell has gotten Waitwell out of jail, and that it is best for her to go hide in Ms. Millamant's closet until the drama ends. Mincing ends by saying that Ms. Millamant has sent her to bring Sir Wilfull to her, perhaps to wed him rather than lose 6,000 pounds.
Act V Scene II opens on another room in Lady Wishfort's house where Mrs. Fainall, Lady Wishfort, and Ms. Marwood now converse. The scene begins with Lady Wishfort thanking Ms. Marwood profusely, but turns more tense when Lady Wishfort accuses Mrs. Fainall of being part of the scheme, which Mrs. Fainall denies, stalking off in faked anger. Lady Wishfort goes into a long monologue about how she educated her daughter, Mrs. Fainall, regarding men, raised to be scared and averse of of any man at all, including priests.
Fainall now enters and demands that, in return for keeping his wife's, her daughter's, affair secret, he should be given the 6,000 pounds of Ms. Millamant's inheritance along with the rest of his wife's inheritance (which he attempts to secure as whole by forbidding Lady Wishfort ever to wed). Ms. Marwood helps push Lady Wishfort down the path to accepting this extortion by continuing to remind Lady Wishfort of her daughter's situation.
Ms. Millamant and Sir Wilfull now enter the room as well. Ms. Millamant announces that she will be wedding Sir Wilfull and that to prove she had no hand in the plot, Mirabell will be coming shortly to see her cancel any contract she had with him and give herself over to Sir Wilfull. Though Lady Wishfort does not want to see Mirabell, Ms. Millamant convinces her that if he is not allowed to come he may refuse to let his contract with Ms. Millamant go.
Mirabell enters and immediately asks forgiveness and pity from Lady Wishfort. Sir Wilfull supports Mirabell, commenting on how Lady Wishfort should accept his forgiveness as a Christian and how moving Mirabell's speech is. Lady Wishfort agrees begrudgingly to at least forget Mirabell, so long as he resigns the contract with Ms. Millamant.
Scene III opens on the same room shortly after, with Lady Wishfort, Ms. Millamant, Sir Wilfull, Mirabell, Fainall, and Ms. Marwood present. Fainall is in the process of demanding an answer about the inheritances from Lady Wishfort, but she says that she now cannot sign over the 6,000 pounds since she has agreed to let Ms. Millamant marry Sir Wilfull. Ms. Millamant and Mirabell rub this fact in, evidently having quickly re-schemed to put this roadblock in Fainall's plot. The tables quickly turn, as Mirabell pledges to save Lady Wishfort from Fainall's wrath and she thanks him and promises him Ms. Millamant and her inheritance if he can save her family from scandal.
Mrs. Fainall, Foible, and Mincing now enter, further crowding the stage. Fainall threatens to ruin Mrs. Fainall, who threatens him back. Waitwell enters soon after, followed by Petulant and Witwoud who have just awoken after their drunken escapade. Mirabell now pulls out the final piece of evidence, a contract written before Mrs. Fainall married Fainall that stated her inheritance, the last of Lady Wishfort's money that Fainall could have laid claim to, is signed over to Mirabell. Fainall attempts to attack Mrs. Fainall but then runs offstage, shouting a last threat to Mirabell, with Ms. Marwood quick behind him. Lady Wishfort praises her daughter and pardons "Sir Rowland" and Foible. Ms. Millamant says that Sir Wilfull has compassion upon lovers and so will forgive her for marrying Mirabell; Sir Wilfull agrees and will go abroad as planned. Lady Wishfort gives her blessing to Mirabell and Ms. Millamant. They call upon another dance that was set to be performed when Sir Rowland was visiting Lady Wishfort, and the play proper ends with Mirabell assuring Lady Wishfort once more that the situation with Fainall, both concerning money and reputation, will be resolved.
The play ends with an epilogue, again technically delivered by an actor rather than a character in the show. The epilogue, delivered by the actress who played Ms. Millamant, again reminds the audience not to judge the play too quickly and not to look too closely at characters in the play to discover who they are meant to be based on in reality.
Lady Wishfort's monologue about Mrs. Fainall's upbringing afraid of men, juxtaposed with her situation of marrying a man just doesn't love to not be found out for an unwed affair, pokes fun at this practice of raising girl children in a way too sheltered from men. Lady Wishfort is, as usual, a heightened character in that she caused her daughter even to be afraid of a priest, who would certainly not pursue marriage with her, and thinking that all this was healthy and would keep her out of trouble with men once grown. The humorousness of this attempt should not be lost on modern audiences, whose mothers and fathers may also have tried to shield them unsuccessfully from the world of sexuality.
A major comedic element of Act V is the sequence of more and more characters appearing onstage, until virtually the entire cast in present in one room. The humor is underlined metatheatricality when Witwoud, upon entering with Petulant, says, "Heyday! what, are you all got together, like players at the end of the last act?" This authorial move reads as if Congreve wanted to jar the audience into remembering they are watching a play so that analysis of the situation is done in a purposeful and perhaps moralistic fashion. The fact that it is uttered by Witwoud, someone outside the main drama of the play by this point, also underscores the comically hyperbolic nature situation itself.
Once he has drawn attention to the occurrences of Act V as the climax of a play through Witwoud's metatheatrical remark, a reader must look to what Congreve is attempting to impart through the play's resolution. Mirabell is ultimately entirely successful, gaining the forgiveness for all he has done from Lady Wishfort, the ability to marry his love Ms. Millamant, praise for having signed Mrs. Fainall's fortune over to himself, and having pardoned the other people he involved in his scheme. Though the quatrain that ends the play seems to state that the meaning of the play was that marriage will always be fraught, it seems that what is said through Mirabell's fate is that handsome, charismatic men can still always come out on top, especially in affairs of love, money, and adultery.
Lady Wishfort suffers greatly during this scene, being reduced to begging for help from a man who once pretended love with her, if only to hold on to some of her money and place in society. During the scene, her cracking makeup is called to attention again, and she continues to address Waitwell as Sir Rowland even after this climax came to be by the discovery that he was not what he seemed to be. Though she seems to find success in the end with Mirabell's promise to keep her money and reputation safe, both she and her daughter, Mrs. Fainall, seem to have their fates and perhaps self-respect ruined.
The epilogue in comparison with the prologue is interesting for the fact that the audience now certainly knows the actress speaking as her character from the play. This serves to even more enforce the idea that the characters themselves beg the audience to not review the play so harshly or take the wrong approach to analyzing it - that is, to focus on who exactly is being parodied rather than the meaning of the entire satire as a work. Again, at least directly following the shows first performances, the characters, and Congreve, were in for disappointment.