Wishaw, Lanarkshire born inside right and later right half Peter Proudfoot began his football career with Wishaw Victoria and had a spell in Scottish League football with Airdrieonians in 1898, also playing for Wishaw Thistle and Wishaw United in 1898 and 1899. He then spent 1899-1900 on the books of Sheffield Wednesday without making a first team appearance for The Owls before signing for Second Division club Lincoln City in 1900, making his Football League debut at centre forward against Grimsby Town on Christmas Day that year. Playing mainly at inside and outside right, but also at right half and even at right back in the spring of 1903, he was a regular for three seasons at Sincil Bank, scoring 21 goals in 88 appearances before returning to Scotland to join St Mirren in 1903.
After a spell with Albion Rovers he returned south to join Southern League club Millwall Athletic in 1904. When he signed for Millwall in 1904, the Daily Express described him as “a big strapping fellow with a fine knowledge of the game”. He made a return to Football League action when he joined newly elected Second Division club Clapton Orient in 1905, where he mainly played right half, scoring once in 32 appearances before a transfer to Second Division rivals Chelsea in April 1906, playing 4 times for Chelsea before the end of the season. He had two further seasons on the fringes at Chelsea, where he was mainly employed at left half, but made only 12 appearances in total for The Pensioners before a transfer to Manchester United in December 1907, but he spent the rest of the 1907-08 season in their reserves and didn’t make their first eleven.
In the 1908 close season he joined Second Division Stockport County where he was a regular in their 1908-09 campaign, initially filling the right half berth and then at centre half, scoring once in 37 appearances before another return to Scotland in the summer of 1909 when he joined Greenock Morton. After a spell with Wishaw Thistle in 1910 he returned to Edgeley Park in March 1911 and made 11 further appearances for Stockport County, his final match for The Hatters coming in a home defeat to Barnsley in March 1913.
Proudfoot then embarked on a coaching career either side of the First World War, and he first became manager of former club Clapton Orient in April 1922 in succession to Billy Holmes, and although the Football Association suspended him from football for six months for financial irregularities in 1928, he remained in the post until May 1929, but he soon returned to replace Arthur Grimsdell in April 1930. His second spell lasted until April 1931 but he once again became Clapton Orient’s manager in January 1935, replacing David Pratt. He then remained in the post until he was sacked for a third and final time in January 1939 as Clapton Orient struggled at the foot of the Third Division (South) table.