Most times 2 teams have played each other in 1 season?

With Celtic and Rangers both more than likely to finish in the top half as always, they will play each other seven times this one season. I've checked, and this has never happened before in the match's history.

I was wondering, have any two teams ever played more competitive games against each other in one season?

Theoretically, if Rangers won the League and Celtic won the cup of the previous year or vice versa, they'd play each other at the start of the season ( equivalent to the community shield.... you do have a community shield right? ) in addition to the 7 other games. So that'd be 8. Oh, and didn't you not have to replay once in the other tournament? If you had to, theoretically that'd be 9 possible times in a season.

No. The Scottish Cup is the only one where replays happen. The League Cup is just 1 leg and Scotland doesnt have a Community Shield type game. They could play more if they met in Europe but Celtic cant stay in Europe for more than 5 minutes so that will never happen

I don't quite remember, but I think Brøndby and FCK met 8 times during one season. 3 times in Royal League (group stage and final), 3 times in the league and cup semi-finals.

Liverpool played Arsenal 7 times in 1979,80 season, they played twice in the League that season and met 4 times in the FA cup semi final which went to 3 Replay's and also met in the Charity shield at the start of the season.

Chelsea have a knack for this, they played Tottenham 5 times in 2001/2, and played Liverpool 5 times 4 seasons in a row between 2004/5 and 2007/08. Can't think of any more than that in English football in recent years.

United faced arsenal 5 times in the 98-99 season
once in the Charity shield
twice in the league
and twice in the FA cup

Blackburn played Villa 5 times last season. 6 times during the whole of 2010.

Wolves played Albion 5 times in 06/07. 2 league, 1 FA Cup & 2 Playoffs!

We have played West Ham 4 times so far, not sure if thats the most out of the Prem teams so far this season

Ahly played Zamalek 5 times in one season before. 2 league matches, 2 champions league matches, and 1 Egyptian cup match.

Roma will play Inter 5 times this season.
Supercoppa
2x Serie A
2x Coppa Italia

Perhaps more if there is a chance of them meeting in CL but I doubt that.