Ivan Šusteršič, also spelled Šušteršič (29 May, 1863 – 20 September, 1925) was a Slovenian lawyer and politician.
He was born in the Carniolan town of Ribnica, then part of the Austrian Empire (now in Slovenia). After finishing grammar school in 1881, he enrolled to the University of Vienna, where he studied law. In 1890, he was among the co-founders of the Catholic Political Society in Ljubljana and in 1896, he was elected to the Austrian Parliament. From 1899, he was a member of the Catholic National Party, later renamed to Slovene People's Party. In the Parliament, he served as president of the Slovene Parliamentary Club from 1907. Between 1909 and 1911, he was president of the largest opposition coalition, the Slovene Union, and between 1912 and 1914, he was president of the Croat and Slovene Parliamentary Club. In 1912, he was named Governor of the Duchy of Carniola. He remained there until October 1918, when he left for Switzerland after a dispute in the Slovene People’s Party. Following his return in December 1922, he was a candidate for the National People's Party in elections in 1923. He was defeated and thereafter withdrew from politics.