Unlike some other animals, the most common symbolism associated with dolphins comes from their behavior rather than their appearance.
Dolphins are considered to be very intelligent animals and therefor symbolize intelligence. They also symbolize playfulness and freedom.
Aside from the obvious meanings there is some stuff that you might not have considered. Right, time for a history lesson again I’m afraid. Sorry about that but it’s needed in this case!
The Greeks and the Romans loved a good bit of mythology and they loved dolphins too. In a few of the myths there are accounts of dolphins bringing humans that were lost at sea safely back to shore. They were also messengers for Poseidon who was the Greek god of the oceans. So one possible meaning of a dolphin tattoo is to pay homage to or show your love for mythology. Weren’t expecting that were you?
There’s more, in Christianity dolphins are said to help transport the spirits of the faithful upon death. Also dolphins are considered a symbol of new life in Christianity so there’s another unexpected meaning for you.
Similarly in Celtic culture the dolphin was also a symbol of new life due to the fact that they believed water could cleanse a person and bring a fresh lease of life. So a dolphin tattoo can certainly represent a new start or a change in your life.
Also, In Hinduism the Goddess Ganga rode a dolphin and getting two dolphins together can represent Ying and Yang in a more artistic way.
Lastly, the Native Americans believe that dolphins symbolize wisdom from within, so a dolphin tattoo can represent wisdom in this sense.