The olympic champion, whose wife Tania Nell gave birth to their first son in October, revealed the couple called the new addition to the family Hussein Mo Farah.
"I wanted Arsenal to be Hussein's middle name, but Tania wasn't having it," he said in an interview with HELLO!
Great photo of all the family!! Meet my son Hussein – the main man of the house hanging with his mum & sisters!!!! pic.twitter.com/KAiHSqRRLj— Mo Farah (@Mo_Farah) November 9, 2015
Farah and Nell also have three-year-old twin girls Aisha and Amani, and Farah has a nine-year-old daughter Rhianna, from a previous relationship.
The interview was the first time the British runner had publicly shared a picture of his son.
Speaking in the interview, Farah said he had "always wanted" a boy and is proud of his newly-grown family.
"Growing up I would never have thought that I'd be a double Olympic champion, with a lovely home and beautiful kids," he added.
Farah announced his joy at having his first son on Twitter on 14 October.
"Yeeeeezzzzzz! It’s a boy! Buzzing to welcome the new man of the house! Mum and baby doing well! #Excited," he wrote.
Nell and Farah, who married in 2010, announced they were expecting their third child together in August with a picture on Instagram.
Farah has previously had his confidence as a father boosted after winning the title of Celebrity Dad of the Year in 2013.
He told the Evening Standard at the time: "I train to be an athlete but there is no training to be a dad and I'm learning all the time.
"This award shows I must doing something right, which is a real confidence boost."
Read the full exclusive interview in HELLO! Magazine, issue 1405, out now.