Fairman joined West Ham United in the summer 1909. He made his debut on 2nd September against Exeter City. Fairman joined a team that included Herbert Ashton, Fred Blackburn, Tommy Caldwell, Frank Cannon, George Kitchen, Frank Piercy, Tommy Randall, Danny Shea, and George Webb.
West Ham beat Carlisle United 5-0 in the first round of the FA Cup. They did even better in the second round beating former FA cup winners, Wolverhampton Wanderers, 5-1, at Molineaux. In this match George Webb scored a hat-trick and Danny Shea got the other two. The Sportsman reported that: "At every point of the game West Ham United were superior to the Wanderers."
The The Athletic News, the country's main football newspaper, produced a long report on the game. "To say that West Ham sprung a surprise at Wolverhampton would to put it mildly. The fact is that most of those who assembled at the Molineux Grounds were inwardly convinced that their favourites would, in racing phraseology, romp home. But right from the kick off they were disillusioned."
For the second season in succession, West Ham were drawn against Queen's Park Rangers. The hugely talented George Webb gave the Hammers the lead but QPR equalized with a goal that should have been ruled offside. Over 18,000 watched the replay that went into extra-time before QPR's centre-forward, William Steer, grabbed the winner.
On 5th November 1910, West Ham United played Brighton & Hove Albion. The following month the The Athletic News reported: "When Brighton opposed West Ham the other week at Upton Park, a wag pointed out that on one side there was a back named Blackman who was a fair man and on the other there was a back named Fairman who was a black man. The latter was Robert Fairman, the long, lithe dark featured player, who, by his good and consistently improving game, has made himself an immense favourite with the West Ham crowd".
After playing in 102 cup and league games Fairman returned to Birmingham City. He only made 16 appearances over the next two seasons.