Neve Campbell has adopted a baby boy.

The 'House of Cards' actress and her actor partner, JJ Feild, welcomed baby Raynor five months ago and the whole family -including son Caspian, six - is ''madly in love''.

Neve, 44, shared the exciting news on Instagram by posting a picture of the family pushing a stroller.

She wrote: ''Sheer joy!!!!....So it's been a secret up until now as JJ and I wanted to wait until it was official but we adopted a beautiful baby boy 5 months ago.

''His name is Raynor and we are madly in love with him.

''Our 6 year old son Caspian is over the moon and asks every morning 'Can I hold my baby? Can I feed my baby? Can I play with my baby.' It's the most incredible thing we've experienced. We're so grateful for this beautiful light coming into our lives and we think of and are grateful to his birth family every day for such an incredible gift.

''This picture was taken moments after our adoption became official and I've been dying to share our news with you all!''

Neve and JJ were first linked together in 2011 and their relationship was confirmed in 2012, just months before she gave birth to Caspian.

Speaking previously about how they chose the unusual moniker for their first child, Neve said: ''We looked through a lot of books and I liked the idea of a unique name.

''I like having a unique name -- it's [my mom's] maiden name, Neve -- and not a lot of people have it. It's nice having something special and different and so I wanted something like that for our son.

''We decided that we'd wait and see and meet him and then decide,'' she explained. ''And ... when he was born we knew we could only remember one name we had looked at and that was Caspian, so it seemed like it was right.''