Gods of Gaul:

Abnoba

Goddess of the hunt, similar to the Roman Diana

Andraste

Goddess of victory

Belenus

God of light; his name means "shining one"

Borvo

God of healing; his name is associated with springs

Cernunnos

God of fertility and animals; referred to as the "horned one"

Damona

Goddess of fertility and healing; her name translates as "divine cow"

Dispater

Roman god of the underworld; his cult thrived in Gaul also

Epona

Goddess of horses

Esus

God equated with the Roman deities Mars and Mercury

Nantosuelta

Goddess of nature; the wife of Sucellus

Nehalennia

Goddess of the sea

Ogmios

Gods of eloquence and knowledge; equated with the Roman hero Hercules

Rosmerta

Goddess who was the native consort of the Roman god Mercury; her name signifies "great provider"

Sirona

Goddess of healing

Sucellus

God of agriculture and forests; also a hammer god (his name means "good striker")

Taranis

God whose name means "thunderer"; compared to the god Jupiter

Teutates

God of war; roughly equivalent to the Roman god Mars

Gods of Britain:

Belatucadrus

God whose name means "fair shining one"

Cocidius

God associated either with forests and hunting (linked with the Roman god Silvanus), or war (equated with Mars)

Condatis

God who personified the joining of two bodies of water in the Tyne-Tees area of North Britain; also conflated with the Roman god Mars

Coventina

Goddess who personified a holy spring (that was reputed to have healing powers)

Cuda

Mother goddess

Latis

Goddess associated with water (and possibly beer as well)

Matres Domesticae

An aspect of the three mothers, who were considered goddesses of the homeland (Britain)

Mogons

God who was worshipped mainly in North Britain; his name means "great one"

Nodens

God of healing; he is related to the Irish god Nuada

Sulis

Goddess of healing, she presided over hot springs in Aquae Sulis (modern Bath); often conflated with the Roman goddess Minerva

Gods of Ireland:

Aine

Goddess of love

Banbha

One of the trio of goddesses who lent their name to Ireland

Boann

Goddess of water and fertility; bore Oenghus to the Daghda

Brigit (Brighid)

Goddess of fertility, healing, and poetry

Cian

The father of Lugh

Cliodna

Goddess of beauty and the otherworld

Creidhne

God of metalworking; one of the trio of craft-gods of the Tuatha De Danaan

Daghda

God of the earth; leader of the Tuatha De Danaan

Danu

Goddess who is a version of the Great Mother; mother of the Tuatha De Danaan

Dian Cecht

God of crafts and healing

Donn

God of the dead; the "dark one"

Eriu

Another of the three goddesses after which Ireland was named

Fodla

Third of the trinity of goddesses of Ireland

Goibhniu

God of the smith; one of three craft-gods of the Tuatha De Danaan

Luchta

God of wrights; one of the triad of craft-gods of the Tuatha De Danaan

Lugh

God whose name means "shining one"

Macha

Goddess of war and fertility; called "Macha the crow"

Morrigan

Godesses of war and death; had a triple aspect; wife of the Daghda

Nechtan

Water-god whose sacred well was a source of knowledge

Néit

God of war; husband of Nemhain

Nemhain

Goddess of war and battle

Nuada

One of the kings of the Tuatha De Danaan

Oenghus

God of youth and love

Ogma

God of eloquence and language

Tuatha De Danaan

The Irish race of gods who descended from the goddess Danu; patrons of magic and arts

Gods of Wales:

Arianrhod

Goddess whose name means "silver wheel" (i.e., the moon)

Blodeuwedd

A maiden of flowers created to be the wife of Lleu Llaw Gyffes

Branwen

The daughter of Llyr

Dewi

God who was represented by the Red Dragon, which has become the emblem of Wales

Don

Mother goddess; the Welsh equivalent of the Irish Danu

Govannon

God of smiths & metalworkers

Gwynn ap Nudd

God of the Underworld

Lleu Llaw Gyffes

God who is the Welsh equivalent of the Irish Lugh

Llyr

God of the sea

Math ap Mathonwy

God of sorcery

Modron

Goddes whose name means "divine mother"