The Alexander Nevsky Cathedral (Estonian: Aleksander Nevski katedraal, Russian: Александро-Невский собор) is an orthodox cathedral on Toompea hill in central Tallinn, Estonia. It was built to a design by Mikhail Preobrazhensky in a typical Russian Revival style in 1894–1900, when the country was part of the Russian Empire. The cathedral is Tallinn's largest orthodox cupola church. It is dedicated to the grand prince of Kiev, and later saint, Alexander Nevsky who in 1242 won the Battle of the Ice on Lake Peipus, near the present-day border between Estonia and Russia. The late Russian patriarch Alexis II started his priestly ministry in the church.

The Alexander Nevsky Cathedral crowns the hill of Toompea which is one of several places where, according to legend, Kalev, father of the hero of the Estonian national epic Kalevipoeg, is said to have been buried. As the USSR was officially non-religious, many churches including the cathedral were left to fall into disrepair. The church has been meticulously restored since the end of the Soviet occupation of Estonia in 1991.