Seakle Greijdanus (1 May 1871 – 19 May 1948) was a Reformed theologian in the Netherlands, who first served in the Reformed Churches in the Netherlands and later in the Reformed Churches in the Netherlands (Liberated). Greijdanus was born in Arum, Friesland and studied theology at the Free University in Amsterdam, where he specialized in dogmatics. As a minister, he served the Reformed churches of Rozenburg, Zuid-Beijerland and Paesens-Moddergat. In 1917 he became professor at the Kampen Theological University. He died in Zwolle.