St. Johanniskirche, Gothic church in Petersdorf, Fehmarn, Germany.

St. Johanniskirche is a church with a rough grey stone tower topped by a steep dark spire and a red brick nave under a red tile roof. Its brick side wall has tall pointed-arch windows with light stone tracery, and a round stair turret with a conical roof stands at the far right corner. The tower rises over 60 metres, the highest on Fehmarn.

St. Johannis was first built in the first third of the 13th century as a two-nave late Romanesque church. Around 1300 a four-nave enlargement was planned, but only the south nave and a Gothic choir were realised. In 1856 a restoration that a source calls "highly barbaric" reshaped the interior, which had originally been white-plastered like the churches of Burg and Landkirchen.

The church is named after John the Baptist, patron of the Westerkirchspiel parish on Fehmarn. The wealth of the island's farmers shows in the furnishings: numerous epitaphs fill the interior, the oldest that of Jürgen Rauert, who died in 1633 aged 49, its Renaissance frame holding a copy after Hans von Aachen's engraving of the Entombment of Christ.

The church is open for daytime visits, and regular viewing opportunities are available by contacting the phone number 04371 3341 for inquiries. It is located in Petersdorf and accessible for visitors exploring the island churches of Fehmarn.

The oldest piece of furnishing is the baptismal font of Gotland limestone from the church's construction period, now placed in a small baptistery in the south nave with no view of the altar. Above it hangs an octagonal font cover of 1779 crowned by a blessing Christ, donated by the chamberlain Hans Lafrentz and his wife Anna née Mackeprang, who also had the pulpit and altar renovated.