The young couple, nicknamed “Romeo and Juliet” by the Italian media, got married in August, after the bank imposed a rule banning marriage between employees aimed at preventing nepotism.
The newlyweds were given 30 days for one to resign so the other could keep their job.
Neither was willing to do this, and so they were both sacked after the deadline expired on Tuesday.
The Vatican bank said in a statement on Wednesday that it had reached the “difficult decision” to end their employment contracts because “the formation of a married couple among employees is, in fact, blatantly contradictory to the current regulations within the institute”.
The bank said that the primary objective of the marriage ban was to avoid the reputational risk of accusations of nepotism, and “avoid the possible emergence of situations of conflicts of interest in the institute’s operations, in order to protect its integrity and service to its clients”.
The added: “This decision, taken with deep regret, was dictated by the need to preserve transparency and impartiality in the institute’s activities, and in no way intended to question the right of two people to be united in marriage.”
The Vatican bank, which has spent much of the past decade cleaning up its books and reputation after an overhaul ignited by several scandals, announced the rule in April.
The policy had been in the pipeline for some time but was reportedly applied only after one spouse of the last remaining married couple among the bank’s staff retired.
The rule, which also bars staff from marrying someone employed by another Vatican institution, was made public only after disgruntled employees shared details with the Italian press.
The Vatican bank has more than €5bn-worth of assets but employs only 100 people in one location.
The newlyweds appealed last month to Pope Francis, who approved the rule, decrying the “unjust” situation in a long letter, according to Il Messaggero.
The newspaper reported that the couple could take the case to the Vatican’s court.
ADLV, the association of Vatican lay workers, had intervened on the couple’s behalf, arguing that “the birth of a new family should not be endangered by bureaucratic regulations”.
It is not the first workers’ dispute to embroil the Holy See.
In May, dozens of employees at Vatican Museums launched an unprecedented legal dispute over job conditions and workplace safety.
They sent a petition to the Vatican’s governorate alleging that the city state’s labour rules “undermine each worker’s dignity and health”, including overtime hours paid at lower rates and insufficient health and safety provisions.