He scored his first goal for new club Manchester City on Saturday following his £100 million signing to the team.
In photos obtained by The Sun, the duo can be seen chatting away as they leave a bar, with the paper reporting that they moved on to a club with friends.
Night out: Jack Grealish, 25, enjoyed a night out in Manchester on Sunday, joining Love Island’s Ellie Brown, 23, on the town (pictured earlier in August)
Jack cut a typically trendy figure in peach-hued trousers teamed with a graphic, long-sleeve T-shirt.
The superstar footballer was also rocking a baseball cap and an impressive gold chain hung around his neck.
Blonde bombshell Ellie teamed ripped jeans with a bright pink, corset style top and added height to her frame in chic heels.
A source told the paper: ‘Drinks were flowing and they were flirting like mad. At one point they nipped outside for a quiet chat with some friends.
Stylish: Blonde bombshell Ellie (pictured in a throwback snap) teamed ripped jeans with a bright pink, corset style top and added height to her frame in chic heels on her night out
‘Later on in the evening, Jack was going to Chinawhite with some of his footballing pals, including teammate Riyad Mahrez and Danny Simpson. Ellie ended up in the same club as them with her pals.’
However a separate source close to Ellie insisted there is ‘nothing’ between the pair and that they simply have mutual friends.
MailOnline has reached out to representatives for both Jack and Ellie for comment.
Earlier in August Jack sparked speculation that he has been using exclusive celebrity dating app Raya, despite being in a relationship with model Sasha Attwood, also 25.
Looking for love Jack? Earlier this month, Jack has sparked speculation that he has been using exclusive celebrity dating app Raya
In a duo of screenshots obtained by The Sun, a profile on the site purporting to be the footballer’s showed Jack on a private jet and another while posing in a Louis Vuitton jacket from a shoot with Sports World.
Raya is an ultra-exclusive private dating app which describes itself as ‘online membership for dating, networking, and making new friends’, where users must go through an exhaustive application process before joining.
The news came after Jack liked a string of Love Island star Lillie Haynes’ sexy bikini pictures on Instagram – before swiftly removing the interaction days later.
The England footballer showed his appreciation for Casa Amor bombshell Lillie’s glamorous photos by liking the snaps from his verified profile.
Lillie, 22, was flattered after noting the likes from Jack on her pictures, including one of her wearing a skimpy white bikini that was shared days after she entered the rival Love Island villa.
‘Flattered’: It comes after Jack liked a string of Love Island star Lillie Haynes’ sexy bikini pictures on Instagram before swiftly removing the interaction days later
‘Stunner’: The England footballer, who’s in a relationship with Sasha Attwood, showed his appreciation for Casa Amor bombshell Lillie’s photos by liking the snaps from his profile
A source told MailOnline: ‘Lillie couldn’t believe Jack even knows who she is, let alone took the time to like her uploads on Instagram.
‘It was disappointing he unliked the photos days later, but it’s possible he didn’t want his girlfriend finding out.
‘She was complimented nonetheless, and hopes one day they’ll cross paths so she can ask him about it.’
The footballer liked a photo of Lillie in a bikini that was shared while she was in Casa Amor on July 26, as well as a snap of the reality star enjoying a glass of bubbles to celebrate her ‘freedom’ after returning from Mallorca and quarantining for five days.
MailOnline contacted Jack and Lillie’s representatives for comment at the time.
It was reported in June that Jack and his childhood sweetheart Sasha had got back together following a brief split, and he considered the model his ‘secret weapon’ off the pitch.
The couple, who were pictured on holiday together in Croatia last month, met while they were teenagers at St Peter’s Roman Catholic Secondary School in Solihull, West Midlands.
Couple: Jack is in a relationship with model girlfriend Sasha Attwood after the childhood sweethearts reportedly reconciled in June following a brief split (pictured in Croatia in August)