Alan Lloyd "Froggy" Thomson (born 2 December 1945), a school teacher, is a former Australian cricketer and Australian rules football umpire.
He played District cricket with the Fitzroy Cricket Club, and took 5/39 against Richmond in their first innings, in his first ever first XI match for the club, on Saturday, 27 March 1965 (he had scored 10 runs for Fitzroy in their first innings on the previous Saturday). 
A right-arm fast-medium who delivered the ball with a windmill-like action, off the "wrong foot". ("bowled off his front leg like a frog in a windmill" hence his name) he played in 4 Tests and one ODI from 1970 to 1971.
Thomson made his first-class debut for Victoria against New South Wales in Sydney in January 1969, taking 6 for 114 in the first innings. In his next match, against the touring West Indians in Melbourne, he took 5 for 76 and 6 for 84. In 1969-70, with the Test team away in India and South Africa, he was the outstanding player of the season, with 55 wickets in 10 matches at an average of 18.74. Against New South Wales in Melbourne he took 5 for 54 and 8 for 87, which remained his best innings and match figures. A number 11 batsman who seldom reached double figures, he hit his top first-class score of 34 not out against Tasmania in Melbourne in January 1970. He toured New Zealand with an Australian team at the end of the season, opening the bowling in the first match against a Test-strength New Zealand team in Auckland and taking five wickets.
At the start of 1970-71 Thomson took 6 for 80 and 3 for 101 in Victoria's tour match against the M.C.C. as the tourists were dismissed for 142 and 341 and lost by 6 wickets. As a result he was called up for the First Test in the 1970-71 Ashes series, having by this stage in his career taken 120 wickets in 22 matches at 20.01, but failed to live up to expectations. In the Fifth Test at Melbourne Thomson bowled bouncers at the England fast bowler John Snow, who had hit Garth McKenzie on the head in the previous Test, and six in one eight-ball over against the captain Ray Illingworth. Thomson was not warned for intimidatory bowling, which Snow thought was partisan umpiring as Snow was repeatedly warned throughout the series. In the Sixth Test, his last, he shared the new ball with Test debutant Dennis Lillee. Like Lillee, he took five wickets in the match - 2 for 94 and 3 for 79, his best innings and match figures in Tests. The series also saw the last Tests of his fellow pace bowlers Graham McKenzie, Alan Connolly and Ross Duncan.
After 1970-71 he played irregularly for Victoria, and two wicketless matches in 1974-75 were his last.
He is famous for taking the first-ever wicket in ODI cricket (Geoff Boycott caught by Bill Lawry for 8 runs) at the MCG on 5 January 1971; it was his only ODI wicket. He was the most economical bowler in the match, taking 1 for 22 off eight 8-ball overs. In 1971-72 he took 4 for 13 off eight 8-ball overs for Victoria against Queensland in Brisbane, his best one-day figures.
He was also a senior Australian rules football umpire, umpiring Senior Grade VFL football, at a time when there was only one field umpire, and before the transformation of the VFL into the AFL. He officiated in six VFL matches between 1970 and 1972.