A dream come true - is it correct

Solution 1:

It is correct. Come is a past participle here, not a simple present. It means a dream [that has/is] come true. The past participle come can be used with the verb be, which is why a dream come true is possible; this is normally possible with all verbs that can be or once could be used with be.

a horse [that was] left behind

a day [that has/is] gone by