Yehoshua Yeshaya Neuwirth (Hebrew: יהושע ישעיה נויברט) (15 February 1927 – 11 June 2013)[2][3][4] was an eminent[5] Orthodox Jewish rabbi and posek (halakhic authority) in Jerusalem.

He was one of the primary students of Rabbi Shlomo Zalman Auerbach and the author of a two-volume Hebrew language treatise, Shemirat Shabbat Kehilchatah — translated into English as Shemirath Shabbath: A practical guide to the observance of Shabbath — a compendium of the laws of Shabbat[6] which is viewed by many as an authoritative work regarding these laws.

During this time, Neuwirth had little access to rabbinic literature, apart from the volume of the popular work Mishnah Berurah that deals with the Shabbat laws.

[8] In 1946 he immigrated illegally to Palestine, and was detained at Atlit camp before being released and travelling to Jerusalem, where he was accepted at the Kol Torah yeshiva.

[14][15] Additionally, 8 of the 32 chapters of this book were devoted to Rabbi Auerbach's rulings on medical halacha.