Fortuna Virilis is one of the many aspects of the Roman Goddess of luck and chance, Fortuna. Her title means "Manly" or "Virile", and it can be supposed that She made boys into men by making them strong and robust, and watching over them through the difficulties of puberty. She was connected with the Love-Goddess Venus (who also "makes boys into men", albeit in a rather different way), and She was worshipped with Venus at the festival of the Veneralia.

The Veneralia was a holiday of Venus Verticordia ("Venus the Changer of Hearts") held on April the 1st, the date of the founding of Her temple on the Aventine Hill, in which rites to Fortuna Virilis seem to have played a part. Perhaps the two taken together were meant to inspire and protect young men as they began to take an interest in sex and/or girls as they grew; and further evidence of a link between the two Goddesses is found in the fact that a shrine of Fortuna Virilis was located besides an altar to Venus of the Basket, though exactly where in Rome they were located is unknown.

Fortuna Virilis also had a temple in Rome, said to have been built, once again, by the early Roman King Servius Tullius, who was so famously devoted to Fortuna that there is a legend they were lovers. There is some confusion as to where this temple stood—it has been identified with that of Mater Matuta in the Forum Boarium, which is most likely incorrect. In the present-day Forum Boarium stands a nicely proportioned little temple that was also once believed to belong to Fortuna Virilis. This temple dates from late Republican times and is an excellent state of preservation (it even has a roof on it, fer cryin' out loud) because it was converted to a church in the 9th century CE. This identification, however, is thought to be incorrect as well, and the little temple is now generally identified with Portumnus, the God of Doors and Harbors.

Fortuna Virilis, though "Manly Luck", was also said to ensure that women were happily married. It was said that matrons prayed to Her to preserve their beauty so that they might continue to please their husbands; but perhaps Her worship among women also reflects that a woman's ability to have children (the duty and supposed dream of every good matron of Rome) was dependant on her husband's virility.

Like Fortuna Respiciens, Fortuna Virilis could be known under a Greek title, in which case She was Tykhe Arrên, meaning the same thing, "Manly Fortune".