Rabbi Solomon Aaron Wertheimer (November 18, 1866 – 1935), was a Hungarian rabbi, scholar, and seller of rare books.
He was born in Bösing in 1866. In 1871 he went with his parents to Jerusalem, where he was educated. By 1890, he was residing in Cairo, Egypt, where he made a living as a rare bookseller and a collector and seller of Cairo Genizah documents. According to Arabist S.D. Goitein, he also published papers on them, but "in a somewhat unscientific way." For five years starting in 1893, he tried to sell the British Library Geniza documents for pennies on the dollar, but many were declined.
He is best known for his midrashic scholarship, his work is one of the two standard midrash compilations from the period (the other is Adolph Jellinek's Bet Ha-Midrasch).
He died in Jerusalem in 1935.
Today, his midrashim are normally printed in a combined two volume set edited by his grandson A. J. Wertheimer. Also entitled Batei Midrashot (Jerusalem: 1967), the work brings together midrashim from Batei Midrashot and Leket Midrash with notes and commentary.