A source told the Sun that Russell, 41, has asked his girlfriend to marry him, as he wanted 'to do the right thing' by making blonde beauty Laura, 27, his wife.
The soon-to-be-dad was previously married to pop star Katy Perry in 2010, but the pair divorced two years later and Laura and Russell have been in an on-off relationship since.
To mark the special occasion, the newly-engaged couple threw a party at their home in Aston near Henley-on-Thames, Oxfordshire, which was attended by close friends and family - including Laura's famous sister, Kirsty Gallacher.
Hinting at the special reason for the get-together, Kirsty shared a snap with her sister to her Instagram account with the caption: 'Congratulations to my gorgeous sister @daisypoppets ❤️❤️❤️'
Giving an insight into the couple's fiercely private life together, a source told the Sun: 'Russell didn't want a big fuss this time after his very public relationship with Katy. Laura is also keen to keep their romance low-key, so the small, intimate party was very much in keeping with their 'homebods' image.
'As they are becoming parents, Russell wanted to do the right thing and make Laura his wife. She's delighted he asked.'
Also in attendance at the bash was friend and Footballers' Wives actress Susie Amy, with Kirsty sharing a snap of the pair enjoying the day to her Instagram account. She captioned the photo: 'Gorgeous day with @susieamy et al Brand/Gallacher family day! 🎈🎈'
This will be the second time Russell ties the knot, after his marriage with Katy Perry ended after 14 months. The comedian has been linked to other stars in the past, including Kate Moss, Courtney Love, Geri Halliwell and Jemima Khan.