In a few cases, essentialy the same word has a different spelling which reflects a different pronunciation. However, in most cases, the pronunciations of the words is the same, or nearly so.

UK: colour, flavour, honour, neighbour, rumour, labour...

US: color, flavor, honor, neighbor, rumor, labor...

 

UK: theatre, goitre, litre, lustre, mitre, nitre, reconnoitre, saltpetre, spectre, centre, titre; calibre, fibre, sabre...

US: theater, goiter, liter, luster, miter, niter, reconnoiter, saltpeter, specter, center...

 

UK: organise, realise, recognise

US: organize, realize, recognize 

 

UK: amoeba, anaemia, anaesthesia, caesium, diarrhoea, gynaecology, haemophilia, leukaemia, oesophagus, oestrogen, orthopaedic, paediatric.

US: ameba, anemia, anesthesia, cesium, diarrhea, gynecology, hemophilia, leukemia, oesophagus, estrogen, orthopedic, pediatric.

 

UK: counsellor, cruellest, modelling, quarrelled, signalling, traveller, and travelling

Us: counselor, cruelest, modeling, quarreled, signaling, traveler, and traveling