A batsman and occasional wicket-keeper, Dennis took part in seven First-Class matches for Nottingham, mostly against Sheffield Cricket Club. He also played against Hampshire and, in 1826, captained Nottingham against a combined Sheffield and Leicester team. At 47, he was the oldest man in the side.
At that time he was landlord of the Eclipse Inn, Chapel Bar and was clearly a man of some wealth – in 1815, he stood to lose £120 on bets he laid during one particular Nottingham game; fortunately the match was won.
Dennis had played for Nottingham since 1800 but announced his retirement in 1828, due to failing eyesight. His fans begged him to appear in 1829, which he did in two final matches. On 16 November 1831, Dennis suffered a stroke while in the Bell Inn and was carried by its landlord, Mr Clarke - later to take over the Trent Bridge Inn and establish the ground we know today - back to the Eclipse, where he died shortly afterwards, only a month after the death of his wife. Writing in 1853, J.F.Sutton notes, "Dennis’s memory still lives in the memory of thousands".