A Chaste Maid in Cheapside presents multiple plots centered around the marriage of Moll Yellowhammer, a chaste maid, who is daughter to the ambitious goldsmith, Yellowhammer. He hopes to marry her off to the philandering Sir Walter Whorehound but Moll loves Touchwood Junior, a poor but gallant young man. In return for Moll’s hand, Sir Walter promises Yellowhammer that Moll's brother Tim can marry his wealthy, welsh niece. In reality, Sir Walter’s niece is one of his mistresses, who has no land, title, or wealth. Despite pursuing Moll, Sir Walter is also having an affair with the wife of Allwit, a willing cuckold, who has given his blessing on the affair in return for financial support.
Elsewhere, Touchwood Senior, a prodigiously fertile and promiscuous man, must separate from his wife in order to avoid another pregnancy, which would cause them financial ruin. However, before he leaves, he comes into contact with the Kixes, an aging couple who are desperate to conceive but are running out of time and hope. If they do not conceive, Sir Walter will inherit the fortune on which they depend. Torchwood Senior spots his opportunity and, informing the couple that he has a special fertility potion, he sends Sir Kix off on a long horse ride while he impregnates Lady Kix. Truly grateful, Sir Kix promises to support Touchwood Senior’s family.
Desperate not to marry Sir Walter Whorehound, Moll flees her parents' home the day before the wedding. However, while while attempting to cross the River Thames, she is found drenched through and seems to fall sick when she is brought home. Meanwhile, Touchwood Junior and Sir Walter fight over Moll in the street, and both seem severely wounded. Sir Walter believes that he is near death and he begins to repents all of his sins in desperation. He condemns the Allwits for allowing him into their marriage. In return they kick him out and plan to sell off all the gifts he has given them and move away.
Touchwood Senior brings word to a sickly Moll that his brother has died. Moll faints and appears to die, and all agree that the young lovers deserve a joint burial. As the funeral commences, Moll and Touchwood Junior are revealed to be alive and grief turns to celebration. The couple are wed, and it is revealed that Tim and the welsh "niece" had also been wed earlier that day. Touchwood Senior announces that Sir Walter has been imprisoned for debt as they all celebrate a fortuitous end to their problems.