R. Joseph b. Isaac Rosen (d. 1885), Russian rabbi and author. Rosen was born in Gorodok, Belorussia. His father intended him for a business career, but he early displayed unusual scholarly abilities and studied for the rabbinate. His first position was in Gorodok near Vitebsk, and in 1864 he was appointed rabbi of Telz (Telsiai). In 1873 he was appointed rabbi of Slonim, succeeding the renowned R. Joshua Isaac Shapira, known as "Eisel Harif." The period of his rabbinate at Slonim was exceptionally difficult for him. The maskilim of Slonim had begun to organize themselves and made considerable progress. Nevertheless, as a result of his moderation and conciliatory ways, his rabbinic authority remained unimpaired, and he enjoyed the respect of both the Hasidim and the maskilim. In 1881 a fire broke out in the city, as a result of which about 75% of its Jewish inhabitants were left homeless. R. Rosen placed himself at the head of an organization to rehabilitate them, and through his organizational ability and moral influence he succeeded in effecting the rebuilding of the homes and the erection of new and modern communal buildings. R. Rosen's daughter married R. Isaac Jacob Reines.

All his works, which display his profound learning, include his name in their titles. They are Edut bi-Yhosef (Vilna, 1866), novellae to the Shulhan Arukh, Yoreh De'ah; Porat Yosef (Warsaw, 1884), responsa and novellae to the Shulhan Arukh, Hoshen Mishpat, and She'erit Yosef (ibid., 1914), responsa and halakhic clarification.

מתוך ההקדמה: חתני ... מו"ה יצחק יעקב ריינעס נ"י אב"ד דשוקיאן ... עבר על כל פני חיבורי זה, לסדרו ולהעמידו על נכון להביאו לבהד"פ, אף גם הוסיף הגהות נכונות ... כן ... חתני ... כמר אלעזר בנימין דאבקין נ"י >בהרב ... מו"ה יוסף דאבקין נ"י מווילקאמיר< ... הי' בעזרי, בעטו היפה ... להוציא פרי עשתנותי חוצה. בשולי ההקדמה הנ"ל: הקדמה הארוכה זאת, שאינה מכתיבתי ממש ... עמסתי זאת על חתני ... כמר אלעזר בנימין דאבקין ... שהוא יעריכנה כנאות, אחרי שידיו רבי לו במלאכת הכתיבה ... אנכי רשמתי לפניו בקוצר מלין. [2], 48 עמ', עם שער מיוחד: ספר עדות ביהוסף והוא כולל חלק אחד מדרשותי אשר דרשתי במקהלות עם תמידין כסדרן שבתות ורגלים ומועדים ... בהלכות ואגדות ...