The Old Inn likely dating from 1780-1820 with later alterations carried out circa 1900 and 1938/9.
Probably originally simply known as the Corner Beer House.

The Old Inn in Circa 1900
The first recorded use of the name “Old Inn” comes in 1898 when Offilers Brewery of Derby bought it (source brewery history.com).
This was after the demise of the previous owner Robert Bingley 1816-1898). Robert was the son of James Bingley 1796-1881) a framework knitter in the village. By the 1841 census Robert is married to Catherine Darnell from Blaby (1816-1873) and is trading as a malster (the preparation of grain for brewing). In the same year (Leicester Journal 29th October) he appears to inherit some of the estate of George Bunting a Victualler from Leicester. The Leicester Mercury of 25th November reports him complaining about George Tebbutt for being drunk in the street opposite his pub, according to Tebbutt this was just because he hadn’t got drunk in Bingleys pub! Whatever, good evidence of him here at least by 1848. A very successful man by 1854, when The Leicester Journal of the 31st March advertises some of his properties for sale by auction , including a house, malting offices, buildings, 15 acres of land, and 5 tenements (Cottages). Tragically in 1857 he loses son Walter, who drowns in the river Soar by Enderby Mill. At the age of 45 in 1861 he describes himself as malster, Grazier, and Victualler, so now growing the grain and processing it to make beer for sale in the Corner Beer House, this surely must be the forerunner of the Old Inn. 1871 census and now aged 55 and trading as a Grazier, and Beer House Keeper.
Robert dies on 11th January 1898, followed on the 16th by his daughter Catherine, both are buried in Cosby cemetery.
The new owners, Offilers Brewery accquired it on 28th October 1898 for £1150 and have plans drawn up for repairs and alterations to the pub, a copy of which is shown above. They retained ownership until 1970 when it was transferred to Bass and valued at £15000.
The earliest recorded tenants of the brewery appear to be John & Minnie Langley mentioned in The Leicester Daily Post dated 16th October 1905.

Plans drawn up for alterations by Offilers Brewery after their purchase.
1909-1929 Ambrose Tomkins 1929 is the tenant and the Leicester Evening Mail of 19th January 1929 reports him as being fined for selling whisky without a licence. He and wife Alice moved to Cosby Road on retirement. At 46 Cosby Road in 1954 he presents a roadside seat to the village in memory of wife Alice.
1932-1941 Harry & Lilian Spence are now in charge and several reports of after hours drinking appear in the local newspapers during the war years. It was during The Spence’s tenancy that the pub was extended to its right hand side when viewed from The Square. This created a singing lounge in the previous open yard area and moved the original entrance on Station road to what was now the front of the pub. This work work was one of the first jobs undertaken by Hubert Bingley the builder in 1938/9, starting out on his own after a disagreement with his father Abraham, his previous employer.
1941-1947 Phillip Spittlehouse. Moved to 19 Station Road on retirement.
1947-1968 Arthur Kenney. Retired to 7 Biddle Road. Died December 3rd 1970.
1968-1985 Dennis & Rita Marples. Dennis had previously worked at Old House Farm
Sources:
As with any local history research continues on this and more information will hopefully be added as it is found, so keep checking for the latest updates. In fact if you can add anything to the above please get in touch via the contact form