Question: What was Jesus' blood type?
Bonus question: Based upon scientific doolbology (the study of blood) what was the Blessed Virgin Mary's blood type?
Answer: Study of blood from the Shroud of Turin, the Sudarium of Oviedo, and the Communion Host of Lanciano reveal the same blood type: AB.
See also: http://www.therealpresence.org/eucharst/mir/lanciano.html
Bonus Answer: There are no personal effects of Mary that have been or could be tested for her blood type. Based upon genetics, the blood type of Mary is assumed to be one of these three: AB or A or B, but not O.
The blood of the bleeding statues of Mary have been studied and overall have come back as AB, as well as having genetic factors closely relating the samples attributed to Jesus.