In wind and rain, the American hit his opening shot out of bounds before running up a quadruple-bogey 8 at the 448-yard first hole at the Southport venue.
O’Meara’s misery contributed to the first group taking a combined 18 shots, with Ryan Moore, who clinched victory for the US in last year’s Ryder Cup at Hazeltine, also carding a double-bogey 6.
Lanky Englishman Chris Wood, who won the Silver Medal as the leading amateur at the Lancashire course in 2008, was the only player in the group to avoid spillage as he opened with a par.
The carnage, though, continued in the next few groups before conditions improved about an hour after O’Meara had got the action underway.
Maverick McNealy, the world amateur No 2, also went out of bounds in the second group as he started with a 7 while Korea’s Jeunghun Wang was in trouble as well down the right as he carded a 6.
Playing in the same group as Wang, 1995 champion Sandy Lyle missed from six feet to save par at the first in conditions that were pretty similar to when he walked off after just 10 holes here in 2008.
O’Meara’s horror start came 12 months after Colin Montgomerie opened with a double-bogey 6 after he’d been handed the honour of getting the event underway at Royal Troon, his home club.
Neil Fenwick is off to a promising start in the PGA EuroPro Tour’s Cobra Puma Golf Championship at Machynys Peninsula in south Wales.
The Edinburgh man opened with a four-under 68 to sit joint-third, three shots off the lead, held by amateur Scott Gregory.
Last year’s Amateur champion, Gregory eagled the last to lead by a shot from Northern Ireland’s Jonathan Caldwell.
England’s George Young shot four-under 67 to take the halfway lead in the McGregor Trophy at Burnham & Berrow, Somerset.
The Kent youngster us is six-under after two rounds in the English Under-16 Boys’ Open Championship and a shot ahead of Estonia’s Joonas Turba.
Top Scot is Royal Montrose youngster Ewan Wheat, sitting joint-31st on six-over (77-71).
Scottish Open qualifier Sandy Scott is among the first batch of players selected to represent Scotland in next month’s Home Internationals at Moortown in Yorkshire.
The Nairn teenager is joined in the team by two other players currently at college in the US, namely Rory Franssen (Inverness) and Ryan Lumsden (Royal Wimbledon).
Scottish Open Stroke-Play champion Liam Johnston (Dumfries & County) has also been picked along with Craig Howie (Peebles), Chris MacLean (Balmore), Craig Ross (Kirkhill), Jamie Stewart (Old Ranfurly) and Euan Walker (Kilmarnock (Barassie)).
Scotland’s two top-ranked players - Robert MacIntyre and Connor Syme - are unavailable for the event, which takes place on 16-18 August.