Strojimir (Serbian Cyrillic: Стројимир; Greek: Στροΐμηρος, romanized: Stroḯmēros) was the co-ruler of the Serbian Principality alongside his two brothers Mutimir and Gojnik, from ca 851 to his and Gojnik's deposition in the 880s after an unsuccessful coup against the eldest Prince Mutimir (r. 851-891).

Peace was subsequently agreed and the two sons of Mutimir; Pribislav and Stefan Mutimirović escorted prisoners towards the border at Rasa.

There Boris gave them rich gifts and was given 2 slaves, 2 falcons, two dogs, and 80 furs by Mutimir.

On July 11, 2006, the Serbian government bought a Byzantine-styled seal in solid gold weighing 15,64 g, most likely belonging to Strojimir (Klonimir's father), at an auction in Munich.

It was presumably crafted outside Byzantium, and has a Greek inscription (KE BOIΘ CTPOHMIP, "God Help Strojimir") and a patriarchal cross in the centre.