The news means that Paul will become a dad for the eighth time at 58 years old, with Hannah, 31, being the fourth mother of his children.
The singer announced the happy news on his official website, releasing a statement confirming that he and his wife are 'delighted' to become parents again together.
Although their message did not reveal the gender of their bouncing bundle of joy, it did say that their little one will arrive in the summer.
The statement read, 'Paul and Hannah are delighted to confirm the wonderful news that they are expecting their third child together.
'Hannah and baby are doing great and the whole family are looking forward to meeting the littlest Weller in the summer.'
The pair already share twin boys Bowie and John Paul who they welcomed into the world in 2012. In the true spirit of rock and roll the couple chose famous baby names for their sons, drawing inspiration from iconic figures in music David Bowie and The Beatles legends John Lennon and Sir Paul McCartney.
Paul with children Leah and Nathaniel
Paul's newborn will bring his ever-growing brood to eight, the same number of children as fellow music legends Sir Mick Jagger and Rod Stewart.
Paul and Hannah married on the Italian island of Capri in 2010, after meeting in 2008 when she provided the backing vocals for his 2008 LP 22 Dreams.
The music legend also has two children with his previous long-term partner Samantha Stock, who he was with for 13 years and shares daughter Jesamine, 17, and son Stevie Mac, 12, with.
Paul shares daughter Leah, 29, and son Nathaniel, 26, with his first wife Dee C. Lee. Dee originally performed as a backing singer with the late George Michael's Wham! before joining The Style Council, Paul's second band, in 1983. The couple married in 1988.
The 58-year-old also has a daughter Dylan, 21, named after singer Bob Dylan, who he shares with former partner Lucy, a make-up artist.