Is seaweed in the monera kingdom?

No , , sea weeds are not included in kingdom Monera but in Kingdon Protista

Seaweeds belong to three kingdoms:

Kingdom Plantae (chlorophyte, or "green" algae seaweeds),

Kingdom Plantae (rhodophyte, or "red" algae seaweeds),

Kingdom Chromista (phaeophyte, or "brown" algae seaweeds)

Kingdom Chromista (xanthophyte, or "yellow-green" algae seaweeds), and

Kingdom Bacteria (cyanophyte, or "blue-green" algae seaweeds).