
In 2018, Scotrail were facing an impending unit shortage. Their newly built class 385's entry to service had been delayed and they were slowly entering service but not in great enough numbers to operate the flagship newly electrified Edinburgh - Glasgow service and a number of DMU units, many of which operated on the E&G pre electrification were heading off lease to other operators.
To combat this, Scotrail took out a year long lease of 10 class 365s, which had recently gone off lease with Great Northern, starting in May 2018. Known as the 'Happy Trains' for their distinctive front ends which looked like a smiling face, the units were popular with enthusiasts and passengers throughout their brief spell in service in Scotland.
The first unit, 365523, arrived on 22nd April 2018 at Springburn from Ely by road, before being hauled from Springburn to Eastfield by road. The next 2 arrivals were also by road. The final 7 movements were by rail. Driver training commenced on 10th May 2018 with a run from Queen Street - Linlithgow. The first passenger run took place on Saturday 22nd June 2018 with 365517+365537 operating the 22.30 service from Waverley - Queen Street.

The 365s operated in pairs on the E&G until December 2018, when they switched to Edinburgh - Dunblane services and operated as 4 car services. Sufficient class 385s were in service by early March 2019 allowing the class 365s to be withdrawn from service, with the final 365 operated services running on 12th March 2019.
After a period of storage between Yoker and Motherwell TMD, all 10 units were hauled south to Crewe for further storage.
Unfortunately the fleet saw no further use and were later scrapped along with the remaining 365s that had been in use with Great Northern upon their withdrawal.
Three class 365 vehicles remain in existence with DMSO 65917 and TSO 72287 from 365524 and DMSO 65975 from 365540 surviving in preservation at the East Kent Railway.
Livery
The livery carried was the Thameslink grey base coat with dark blue doors and Scotrail branding.
Class 365 Unit formation (Scotrail units only)
| Unit Number | Scotrail Livery | Vehicle Numbers | Unit Name |
| 365509 | Grey base with dark blue doors and Scotrail Branding | 65943 72256 72257 65902 | |
| 365513 | Grey base with dark blue doors and Scotrail Branding | 65947 72264 72265 65906 | |
| 365517 | Grey base with dark blue doors and Scotrail Branding | 65951 72272 72273 65910 | |
| 365519 | Grey base with dark blue doors and Scotrail Branding | 65953 77276 77277 65912 | |
| 365521 | Grey base with dark blue doors and Scotrail Branding | 65955 72280 72281 65914 | |
| 365523 | Grey base with dark blue doors and Scotrail Branding | 65957 72284 72285 65916 | |
| 365527 | Grey base with dark blue doors and Scotrail Branding | 65959 72288 72289 65918 | |
| 365529 | Grey base with dark blue doors and Scotrail Branding | 65963 72296 72297 65922 | |
| 365533 | Grey base with dark blue doors and Scotrail Branding | 65967 72304 72305 65926 | |
| 365537 | Grey base with dark blue doors and Scotrail Branding | 65971 72312 72313 65930 | Daniel Edwards (1974-2010) Cambridge Driver |