This is a difficult question for several reasons.

What do we consider a viking raid?

Should the participants be mostly pagan?

Should the participants not be from a royal expedition?

Should the participants be equipped, raised and fight like the vikings did?

The Scandinavian Kingdoms started to be firmly established and then centralised during the 10th and 11th centuries. This correleated with the Kings accepting christianity and at least in theory christianising their subjects.

If the participants in this raid must be pagan, then the last raid will be sometime in the early 1000s.

As Europe centralised and built castles and permanently standing forces through feudalism, the number of easy targets rapidly declined, which meant that only expeditions started by the King (or perhaps a Great Man supported by the King).

If the participants must be out on their own and not commanded by a King, then the early 1000s is again a cut-off date.

Some consider Harald Sigurdsson (Hårdråde)'s attack on England 1066 as the last large-scale viking raid and one might consider it as such, at least in the west. He fell in battle against Harald Godwinsson's Anglo-Saxon Housecarls at Stamford Bridge. He was a King and a christian, and a large part of his force were christian (at least nominally) but were raised, equipped and fought like the earlier vikings.

However, the Swedish medieval Kingdoms embarked on several "crusades" against the Finns, Ingrians and Estonians during the 1100s - the Estonians in particular were strong opponents, counter-raiding Sweden and burning the then capital of Sigtuna (which led to the founding of Stockholm) 1187.

During the latter half of the 1100s, Swedish Kings, raising viking style ledungs raided and plundered Finland, slowly starting to establish control and extract taxes rather than raiding in the early 1200s.

Perhaps the Battle of the Neva 1240, where the Novgorodians under Alexander Nevskij defeated a Swedish army still equipped, organised and raised like viking forces could be said to be the last viking raid. 1280 Sweden formally introduced nobility and granted tax exemption to any man who could raise a fully armoured soldier on horseback.