Parker and McAlpine join six other new faces making their way to Murrayfield next season, including South African prop WP Nel; All Black back and former Junior World Player of the Year, Ben Atiga; and Welsh caps John Yapp (prop) and Richie Rees (scrum-half), while 19 of the club's top performing players have extended contracts.
Head coach Michael Bradley, said: "It's very exciting for Edinburgh Rugby to have secured two very promising young locks at crucial stages of their respective careers.
"While we'll continue to refine the expansive, attacking play for which the club is famous, we're keen to introduce a harder, more aggressive edge to our play, and believe this pair will work tirelessly to lay the platform from which our back division can play.
"Both players have real quality, are exceptionally committed, and will develop into top-class second-rows for Edinburgh Rugby."
At 6'8" and 118kg, 24-year-old Parker is a fast, dynamic ball-carrying second-row, renowned for his pace, contact skills and deft touch in the lineout.
In his early 20s, he captained Haywards Heath before making a big impression with Esher in his debut championship season, before looking to progress his career at a higher level.
The big lock explained that when the call came, he jumped at the chance to pull on the black and red of Edinburgh Rugby.
He said: "I knew that the Edinburgh Rugby coaches had seen some of my tapes so I was delighted to get the chance to meet them and talk about the club's achievements, ambitions and off-field culture.
"It's a massive opportunity for me. To be in the mix with a club like Edinburgh Rugby is really exciting.
"The club's quarter-final win over Toulouse was inspirational and I can't wait to be part of that next season."
McAlpine, the great-nephew of former Scotland caps Donald and Angus Cameron, is tipped as one of the most promising young locks in the Scottish game.
Aigned to city rivals Glasgow Warriors from the conclusion of the 2011 IRB Junior World Championships, McAlpine spent the second half of the season with Edinburgh Rugby, making two appearances against Ulster and Cardiff Blues.
The youngster's commitment to the capital means that the club now boasts two of the leading young locks in the country, as McAlpine is reunited with former age-grade internationalist Grant Gilchrist, who extended his contract earlier this year.
Reflecting on his six months with the club, McAlpine said: "It's been great, the players have been really welcoming. It's been easy to fit in as I've played with so many of the younger players at the club during my time in the Scotland age-grades - it's like a home from home."
McAlpine revealed that witnessing the part played, and the improvements made, by some of the club's youngsters was a key part of him signing for the club.
"Seeing what players like David Denton, Grant Gilchrist and Matt Scott have all achieved as EDP players at Edinburgh Rugby has been a massive inspiration," added McAlpine.
"This summer will be my first full senior pre-season and I can't wait to push on, build my fitness and physicality, put pressure on the other second-rows and see what progress I can make.
"I want to be part of club that's going places and Edinburgh Rugby have proved that they're really stepping up. They've competed at Europe's top table this season - that's where I want to be and that's where I want to play my rugby."
Edinburgh Rugby new arrivals:
South African Free State Cheetahs prop, WP Nel
All-Black centre/full-back and former Junior World Player of the Year, Ben Atiga
Wales prop John Yapp (21 caps)
Wales scrum-half Richie Rees (9 caps)
Georgia number 8, Dimitri Basilaia (23 caps)
Northampton Saints back Greig Tonks
Esher lock Perry-John Parker
EDP lock Robert McAlpine
Perry-John Parker (24), second-row
Date of birth: 25 June 1987 in Crawley
Height: 203cm (6'8")
Weight: 118kg (18st 8lb)
Former clubs:
2011-12: Esher
2009-11 Haywards Heath, N3 (captain, 2010/11)
1999-2009: Worthing Raiders (Senior rugby, N2, aged 17 2004)
Honours
2009-11 - Sussex (captain 2010/2011)
Robert McAlpine (21), second-row
Date of birth: 26 March 1991 in Dundee
Height: 2.01m (6'7")
Weight: 110kg (17st 3lb)
Former clubs/schools: Glasgow Academy, West of Scotland, Stirling County
Honours: Scotland U17, U18, U19, U20
Guinness PRO12
Suite 208, Alexandra House,
The Sweepstakes
Ballsbridge, Dublin 4, Ireland