A shofar (Hebrew: שופר‎) is a horn, traditionally that of a ram, used for Jewish religious purposes. Shofar-blowing is incorporated in synagogue services on Rosh Hashanah and Yom Kippur. Shofar come in a variety of sizes.

The shofar is mentioned frequently in the Hebrew Bible, the Talmud and rabbinic literature. The blast of a shofar emanating from the thick cloud on Mount Sinai made the Israelites tremble in awe (Exodus 19, 16).

The shofar was used to announce holidays (Ps. lxxxi. 4), and the Jubilee year (Lev. 25. 9). The first day of the seventh month (Tishri) is termed "a memorial of blowing" (Lev. 23. 24), or "a day of blowing" (Num. xxix. 1), the shofar. They were for signifying the start of a war (Josh. 6. 4; Judges 3. 27; 7. 16, 20; I Sam. 8. 3). Later, it was also employed in processions (II Sam. 6. 15; I Chron. 15. 28), as musical accompaniment (Ps. 98. 6; comp. ib. xlvii. 5) and eventually it was inserted into the temple orchestra by David (Ps. 150. 3). Note that the 'trumpets' described in Numbers 10 are a different instrument, described by the Hebrew word 'trumpet' (Hebrew: חצוצרה‎; ḥaṣoṣrah), not the word for shofar (Hebrew: שופר‎).