Anthonie Blocklandt van Montfoort, Anthonie van Blocklandt or Anthonie van Montfoort was a Dutch painter.

He was born in Montfoort, where his father was at one time mayor. He went to learn under Hendrick Sweersz. in Delft and Frans Floris in Antwerp. In 1552 he returned to Montfoort, where he married the daughter of the then mayor.

Blocklandt then settled in Delft, where he produced paintings for the Oude Kerk and the Nieuwe Kerk, later lost to the beeldenstorm. Also he painted a work for the Janskerk (Gouda) called De onthoofding van Saint-Jacob, now in the museum there. He died in Utrecht.

In 1572, Blocklandt made a trip to Italy, after which he settled for good in Utrecht, joining a guild there in 1577. In 1579, he painted his best known work, the triptych The Assumption of Mary that is now in the Basilica of St. Martin in Bingen am Rhein.

According to Carel van Mander, Blocklandt painted biblical scenes, mythological subjects and portraits. He is early-Mannerist in style and he and Joos de Beer (another pupil of Floris) were responsible for the Mannerist style begun by Utrecht artists around 1590. Van Mander wrote that De Beer had many paintings by Blocklandt in his workshop that his pupil Abraham Bloemaert later copied. Few works can definitely be attributed to him. One of these is "Joseph interpreting Pharaoh's dream", now in the Centraal Museum in Utrecht.

He was also the teacher of the Delft portrait painter Michiel Jansz van Mierevelt.