The discovery was made by a member of the public walking past the church in Lyndhurst on Wednesday morning.
The head, found dumped in the church porch, was taken away instantly and the area cleaned.
The New Forest has seen a spate of grim discoveries in recent years.
In May a deer's head and upside down wooden cross was found on a memorial stone in Burley, a deer's head was also left among goods at a church food bank in 2021.
An inverted cross and the number 666 was painted on the door of the part-12th Century St Peter's Church in Bramshaw in November 2019
Sheep were also found fatally slashed and sprayed with a pentagon symbol in the village.