Oscar-winner Weisz landed the coveted Best Actress trophy for her portrayal of Blanche Dubois in a production of Tennessee Williams classic A Streetcar Named Desire.
Law was honoured with the award for Best Shakespearean Performance for his leading role in Hamlet, which he later reprised on Broadway.
Mark Shenton, chairman of the Critics' Circle, the body which votes for the awards, insists the pair proves Hollywood stars can flourish in the theatre as well as onscreen.
He says, “Celebrity casting is viewed a little suspiciously, but Jude Law and Rachel Weisz proved they can still cut it.”
The other main prizes went to Mark Rylance, who was named Best Actor for his role in Jerusalem, which also took the award for Best New Play, while Spring Awakening was crowned Best Musical at the ceremony in London on Tuesday (26Jan10).