St. Johannes Baptista, Catholic parish church in Altenkessel, Saarbrücken, Germany.

St. Johannes Baptista is a Gothic Revival basilica in Altenkessel, built of rough dark grey-brown stone. Its square tower has a pointed-arch doorway framed in reddish stone, stacked pairs of narrow arched windows, a round clock face, and a steep slate pyramidal spire with a small triangular dormer. The interior has three naves of four bays, clustered columns, ribbed vaults painted with animal, plant and ornamental motifs, and a star vault over the crossing.

The church was built in 1902 and 1903 according to designs by Wilhelm Hector. After World War II, extensive restorations were needed to address war damage and issues caused by ground subsidence.

The carved pulpit shows the four Western Church Fathers: Jerome, Ambrose of Milan, Augustine of Hippo and Pope Gregory the Great. Of the church's original altars, only the Marian altar survives. The three choir windows depict scenes from the life of John the Baptist, the church's patron.

The church stands in Altenkessel, a district of Saarbrücken, and is listed as an individual monument in the Saarland heritage register. The weekday church is the converted crypt beneath the sacristy, rebuilt for that purpose in 2000. The organ on the gallery, built by Friedrich Weigle in 1912, has 30 registers on two manuals and pedal.

Three windows in the choir section display scenes from the life of John the Baptist, depicting key episodes from his story. Outside the church stands a Lourdes grotto that serves as a separate outdoor prayer space for visitors.