The former Hearts captain recently left Leeds, having moved to Elland Road last summer despite a trial at Rangers.
"I'm excited to come here from Leeds and on the first day it felt like it was the right decision," Zaliukas told the club's website.
"It's a brilliant stadium and it's going to be fun to play here."
Zaliukas played more than 200 times for Hearts over seven years, but made just 15 appearances for Leeds last term.
His first competitive match for Rangers could be against Hibs in the Challenge Cup on 5 August.
The Ibrox outfit's first Scottish Championship fixture of the campaign is against Hearts at Ibrox on 10 August.
"I think the Championship is going to be a very interesting league because Hearts and Hibs are in here, and even Falkirk and Queen of the South are going to be tough teams," the 30-year-old added.
"I think our squad could compete straight away in the Premiership, everyone is experienced and top players. I think we are going to have a very good squad."
Rangers have also added former St Mirren defender Darren McGregor to their ranks this summer.

Avon and Somerset Police wants to raise the cost of the course from £80 to £95 to help pay for its road policing unit.
The Alliance of British Drivers said the police should not be funded by people "who hadn't done much wrong".
Police and Crime Commissioner Sue Mountstevens said she would not comment on the proposal, which would be discussed later on Monday.
Alliance spokesman Bob Bull described the courses as "not about safety", "more about making money" and a "self-funding merry-go-round.
He said people who were driving at "marginally over" the speed limit should not be penalised and that the police should be concentrating on catching drivers travelling at well over the limit.
In the report, the panel said it hoped the price rise would protect the unit from further cutbacks.
The course is offered to drivers who are caught travelling at 10% above the speed limit plus two mph, but not more than 10% plus nine mph.
At the new price the course would be £5 short of the £100 fixed penalty, but without drivers getting points on their licences.
A motorist who has attended one of the courses within the past three years is not eligible to have the option of attending again.
RAC head of external affairs Pete Williams described the increased cost as "an unwelcome surprise for drivers".
Mr Williams said with more than one million motorists attending the courses each year "there is big money to be made, either by the police or those running the courses".
Staffordshire £80
North Wales £85
Gloucestershire £90
Surrey £95
City of London & Metropolitan £97
Wiltshire Not offered
Source: National Association of Driver Intervention Providers

The value of the deal has not been not disclosed.
The acquisition will add more than 60 employees and more than 6,000 fleet assets to Aggreko's Rental Solutions business.
Glasgow-based Aggreko said it planned to fully integrate Dryco into its North America business.
It also intends to develop "expansion plans to enter additional sectors and global markets".
Dryco specialises in moisture control, drying, heating, and cooling applications for a number of industries, including shipping, manufacturing, food processing and construction.
The company, which operates 10 full-service locations in North America, posted revenues last year of $19m (Â£14.6m).
Aggreko chief executive Chris Weston said: "This acquisition combines the deep technical strength of two highly respected market leaders and provides our customers with an unparalleled range of solutions that can address their HVAC (heating, ventilation and air conditioning) and moisture control needs.
"It also gives Aggreko an opportunity to further support our rapidly expanding customer base within the shipping, food and beverage and painting and coatings industries."
Lithuanian defender Marius Zaliukas has signed a two-year contract with Rangers, after impressing during a trial with the Ibrox club.
[NEXT_CONCEPT]
A plan to increase the cost of speed awareness courses has been criticised as a "self-funding merry-go-round".
[NEXT_CONCEPT]
Temporary power suppler Aggreko is expanding its offering in the United States by buying industrial climate control equipment specialist Dryco.