The answer to this question really varies depending on your ancestry and/or community custom. Allow me to share some information: Jewish men and boys traditionally wear a small fringed tallit (lit.: “cloak”) under their shirts throughout the day. This garment is known as a tallit kattan (a “small tallit”). Children as young as age 3 are taught to wear this light, four-cornered garment.

The tallit worn during prayer is much larger, and is known as a tallit gadol (“large tallit”).

Among Western European and Oriental Jews, boys begin wearing the tallit gadol from the age of bar mitzvah or even earlier.

Traditionally, Eastern European Jewish men begin wearing a tallit gadol for the daily prayers after marriage. Customarily, the tallit is a gift from the bride or her family.

Why is that? There are a number of reasons given for this custom.

Many point to the fact that the verse in the Torah “if a man shall take a woman . . . ” immediately follows “you shall make for yourself fringes.” (Deuteronomy 22) This juxtaposition serves as basis for the custom that people begin wearing the large tallit only after marriage.

On a mystical level, it is explained in Chassidic literature that this is connected to the notion that the large tallit, which surrounds the wearer, is associated with an encompassing joyful light of G‑d that is only attained after marriage.

I should point out that the above only applies to practicing Jews who are scrupulous to wear the small tallit under their garments every day. However, those who do not wear them should certainly not push of the mitzvah of tzitzit until marriage.

Click here for more on the tallit gadol.